Drop python 2.6 -> 3.5 support

As stated in our release announcement Stem 2.x will discontinue Python 2.x support now that the PSF has dropped it... https://blog.atagar.com/stem-release-1-8/ https://www.python.org/doc/sunset-python-2/ Presuming our next release is a year out, Python 3.6 is the oldest non-EOL version so picking it as our new minimum requirement... https://devguide.python.org/#status-of-python-branches No doubt this compatibility change will let us make far more simplifications, but for the moment simply addressing low hanging fruit.
author: Damian Johnson <atagar@torproject.org> 2020-01-05 13:28:37 -0800
committer: Damian Johnson <atagar@torproject.org> 2020-01-05 13:28:37 -0800
commit: a396f57c3a55f34bb9f9d5976fc54fcc6561a8c4 (patch)
tree: f34f4715f5e7c5b2edf19558e0a683b984394d1b
parent: 4e21371e88662992fa21bc1f845c05c16ccee4f4 (diff)
parent: bdd376bd9e25dcee54d43a47e10329d92f83cafd (diff)
98 files changed, 475 insertions, 1623 deletions
diff --git a/cache_fallback_directories.py b/cache_fallback_directories.py
index cb413c07..91ad40c0 100755
--- a/cache_fallback_directories.py
+++ b/cache_fallback_directories.py
@@ -8,22 +8,17 @@ Caches tor's latest fallback directories.
 
 import re
 import sys
+import urllib.request
 
 import stem.directory
 import stem.util.system
 
-try:
-  # account for urllib's change between python 2.x and 3.x
-  import urllib.request as urllib
-except ImportError:
-  import urllib2 as urllib
-
 GITWEB_FALLBACK_LOG = 'https://gitweb.torproject.org/tor.git/log/src/app/config/fallback_dirs.inc'
 FALLBACK_DIR_LINK = "href='/tor.git/commit/src/app/config/fallback_dirs.inc\\?id=([^']*)'"
 
 if __name__ == '__main__':
   try:
-    fallback_dir_page = urllib.urlopen(GITWEB_FALLBACK_LOG).read()
+    fallback_dir_page = urllib.request.urlopen(GITWEB_FALLBACK_LOG).read()
     fallback_dir_commit = re.search(FALLBACK_DIR_LINK, fallback_dir_page).group(1)
   except:
     print("Unable to determine the latest commit to edit tor's fallback directories: %s" % sys.exc_info()[1])
diff --git a/cache_manual.py b/cache_manual.py
index 7fe6ea70..5bc68b57 100755
--- a/cache_manual.py
+++ b/cache_manual.py
@@ -8,22 +8,17 @@ Caches tor's latest manual content. Run this to pick new man page changes.
 
 import re
 import sys
+import urllib.request
 
 import stem.manual
 import stem.util.system
 
-try:
-  # account for urllib's change between python 2.x and 3.x
-  import urllib.request as urllib
-except ImportError:
-  import urllib2 as urllib
-
 GITWEB_MAN_LOG = 'https://gitweb.torproject.org/tor.git/log/doc/tor.1.txt'
 MAN_LOG_LINK = "href='/tor.git/commit/doc/tor.1.txt\\?id=([^']*)'"
 
 if __name__ == '__main__':
   try:
-    man_log_page = urllib.urlopen(GITWEB_MAN_LOG).read()
+    man_log_page = urllib.request.urlopen(GITWEB_MAN_LOG).read()
     man_commit = re.search(MAN_LOG_LINK, man_log_page).group(1)
   except:
     print("Unable to determine the latest commit to edit tor's man page: %s" % sys.exc_info()[1])
diff --git a/docs/faq.rst b/docs/faq.rst
index 63800b36..6bbc2f9a 100644
--- a/docs/faq.rst
+++ b/docs/faq.rst
@@ -86,7 +86,10 @@ Ubuntu you can install these with...
 What Python versions is Stem compatible with?
 ---------------------------------------------
 
-Stem works with **Python 2.6 and greater**, including the Python 3.x series.
+Stem works with **Python 3.6 and greater**.
+
+If you require a deprecated Python version then please use Stem 1.8, which was
+compatible with **Python 2.6 and above**.
 
 .. _can_i_interact_with_tors_controller_interface_directly:
 
diff --git a/run_tests.py b/run_tests.py
index 8d7ea45e..d6ced384 100755
--- a/run_tests.py
+++ b/run_tests.py
@@ -7,6 +7,7 @@ Runs unit and integration tests. For usage information run this with '--help'.
 """
 
 import errno
+import io
 import importlib
 import logging
 import multiprocessing
@@ -18,11 +19,6 @@ import time
 import traceback
 import unittest
 
-try:
-  from StringIO import StringIO
-except ImportError:
-  from io import StringIO
-
 import stem.prereq
 import stem.util.conf
 import stem.util.log
@@ -194,20 +190,6 @@ def main():
     println('Nothing to run (for usage provide --help)\n')
     sys.exit()
 
-  if not stem.prereq.is_mock_available():
-    try:
-      import mock
-      println(MOCK_OUT_OF_DATE_MSG % mock.__version__)
-    except ImportError:
-      println(MOCK_UNAVAILABLE_MSG)
-
-    if stem.util.system.is_available('pip'):
-      println("You can get it by running 'sudo pip install mock'.")
-    elif stem.util.system.is_available('apt-get'):
-      println("You can get it by running 'sudo apt-get install python-mock'.")
-
-    sys.exit(1)
-
   test.task.run(
     'INITIALISING',
     test.task.STEM_VERSION,
@@ -215,7 +197,6 @@ def main():
     test.task.PYTHON_VERSION,
     test.task.PLATFORM_VERSION,
     test.task.CRYPTO_VERSION,
-    test.task.MOCK_VERSION,
     test.task.PYFLAKES_VERSION,
     test.task.PYCODESTYLE_VERSION,
     test.task.CLEAN_PYC,
@@ -442,7 +423,7 @@ def _run_test(args, test_class, output_filters):
     traceback.print_exc(exc)
     return None
 
-  test_results = StringIO()
+  test_results = io.StringIO()
   run_result = stem.util.test_tools.TimedTestRunner(test_results, verbosity = 2).run(suite)
 
   if args.verbose:
diff --git a/setup.py b/setup.py
index 8b6f1e4b..52b62dca 100644
--- a/setup.py
+++ b/setup.py
@@ -7,7 +7,7 @@
 #
 # * Recache latest information (cache_manual.py and cache_fallback_directories.py)
 #
-# * Test with python2.6, python2.7, python3, and pypy.
+# * Test with python3 and pypy.
 #   |- If using tox run...
 #   |
 #   |    % tox -- --all --target RUN_ALL,ONLINE
@@ -92,11 +92,7 @@ To install you can either use...
 
   pip install stem
 
-... or install from the source tarball. Stem supports both the python 2.x and 3.x series. To use its python3 counterpart you simply need to install using that version of python.
-
-::
-
-  python3 setup.py install
+... or install from the source tarball. Stem supports Python 3.6 and above.
 
 After that, give some `tutorials <https://stem.torproject.org/tutorials.html>`_ a try! For questions or to discuss project ideas we're available on `irc <https://www.torproject.org/about/contact.html.en#irc>`_ and the `tor-dev@ email list <https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-dev>`_.
 """.strip()
diff --git a/stem/__init__.py b/stem/__init__.py
index 66bc24b5..3600e920 100644
--- a/stem/__init__.py
+++ b/stem/__init__.py
@@ -722,7 +722,7 @@ class SocketClosed(SocketError):
 class DownloadFailed(IOError):
   """
   Inability to download a resource. Python's urllib module raises
-  a wide variety of undocumented exceptions (urllib2.URLError,
+  a wide variety of undocumented exceptions (urllib.request.URLError,
   socket.timeout, and others).
 
   This wraps lower level failures in a common exception type that
diff --git a/stem/client/__init__.py b/stem/client/__init__.py
index 307bd4e4..2abeac88 100644
--- a/stem/client/__init__.py
+++ b/stem/client/__init__.py
@@ -64,14 +64,6 @@ class Relay(object):
   """
 
   def __init__(self, orport, link_protocol):
-    # TODO: Python 3.x adds a getbuffer() method which
-    # lets us get the size...
-    #
-    #   https://stackoverflow.com/questions/26827055/python-how-to-get-iobytes-allocated-memory-length
-    #
-    # When we drop python 2.x support we should replace
-    # self._orport_buffer with an io.BytesIO.
-
     self.link_protocol = LinkProtocol(link_protocol)
     self._orport = orport
     self._orport_buffer = b''  # unread bytes
diff --git a/stem/client/cell.py b/stem/client/cell.py
index 57a71749..83888556 100644
--- a/stem/client/cell.py
+++ b/stem/client/cell.py
@@ -354,10 +354,10 @@ class RelayCell(CircuitCell):
 
       digest_packed = digest.digest()[:RELAY_DIGEST_SIZE.size]
       digest = RELAY_DIGEST_SIZE.unpack(digest_packed)
-    elif stem.util._is_str(digest):
+    elif isinstance(digest, (bytes, str)):
       digest_packed = digest[:RELAY_DIGEST_SIZE.size]
       digest = RELAY_DIGEST_SIZE.unpack(digest_packed)
-    elif stem.util._is_int(digest):
+    elif isinstance(digest, int):
       pass
     else:
       raise ValueError('RELAY cell digest must be a hash, string, or int but was a %s' % type(digest).__name__)
diff --git a/stem/client/datatype.py b/stem/client/datatype.py
index 5de5e445..1db46a28 100644
--- a/stem/client/datatype.py
+++ b/stem/client/datatype.py
@@ -138,7 +138,6 @@ users.** See our :class:`~stem.client.Relay` the API you probably want.
 import binascii
 import collections
 import hashlib
-import struct
 
 import stem.client.cell
 import stem.prereq
@@ -183,7 +182,7 @@ class _IntegerEnum(stem.util.enum.Enum):
     Provides the (enum, int_value) tuple for a given value.
     """
 
-    if stem.util._is_int(val):
+    if isinstance(val, int):
       return self._int_to_enum.get(val, self.UNKNOWN), val
     elif val in self:
       return val, self._enum_to_int.get(val, val)
@@ -367,7 +366,7 @@ class Field(object):
 class Size(Field):
   """
   Unsigned `struct.pack format
-  <https://docs.python.org/2/library/struct.html#format-characters>` for
+  <https://docs.python.org/3/library/struct.html#format-characters>` for
   network-order fields.
 
   ====================  ===========
@@ -380,68 +379,30 @@ class Size(Field):
   ====================  ===========
   """
 
-  def __init__(self, name, size, pack_format):
+  def __init__(self, name, size):
     self.name = name
     self.size = size
-    self.format = pack_format
 
   @staticmethod
   def pop(packed):
     raise NotImplementedError("Use our constant's unpack() and pop() instead")
 
   def pack(self, content):
-    # TODO: Python 2.6's struct module behaves a little differently in a couple
-    # respsects...
-    #
-    #   * Invalid types raise a TypeError rather than a struct.error.
-    #
-    #   * Negative values are happily packed despite being unsigned fields with
-    #     a message printed to stdout (!) that says...
-    #
-    #       stem/client/datatype.py:362: DeprecationWarning: struct integer overflow masking is deprecated
-    #         packed = struct.pack(self.format, content)
-    #       stem/client/datatype.py:362: DeprecationWarning: 'B' format requires 0 <= number <= 255
-    #         packed = struct.pack(self.format, content)
-    #
-    # Rather than adjust this method to account for these differences doing
-    # duplicate upfront checks just for python 2.6. When we drop 2.6 support
-    # this can obviously be dropped.
-
-    if stem.prereq._is_python_26():
-      if not stem.util._is_int(content):
-        raise ValueError('Size.pack encodes an integer, but was a %s' % type(content).__name__)
-      elif content < 0:
-        raise ValueError('Packed values must be positive (attempted to pack %i as a %s)' % (content, self.name))
-
-    # TODO: When we drop python 2.x support this can be simplified via
-    # integer's to_bytes() method. For example...
-    #
-    #   struct.pack('>Q', my_number)
-    #
-    # ... is the same as...
-    #
-    #   my_number.to_bytes(8, 'big')
-
     try:
-      packed = struct.pack(self.format, content)
-    except struct.error:
-      if not stem.util._is_int(content):
+      return content.to_bytes(self.size, 'big')
+    except:
+      if not isinstance(content, int):
         raise ValueError('Size.pack encodes an integer, but was a %s' % type(content).__name__)
       elif content < 0:
         raise ValueError('Packed values must be positive (attempted to pack %i as a %s)' % (content, self.name))
       else:
-        raise  # some other struct exception
-
-    if self.size != len(packed):
-      raise ValueError('%s is the wrong size for a %s field' % (repr(packed), self.name))
-
-    return packed
+        raise
 
   def unpack(self, packed):
     if self.size != len(packed):
       raise ValueError('%s is the wrong size for a %s field' % (repr(packed), self.name))
 
-    return struct.unpack(self.format, packed)[0]
+    return int.from_bytes(packed, 'big')
 
   def pop(self, packed):
     to_unpack, remainder = split(packed, self.size)
@@ -449,7 +410,7 @@ class Size(Field):
     return self.unpack(to_unpack), remainder
 
   def __hash__(self):
-    return stem.util._hash_attr(self, 'name', 'size', 'format', cache = True)
+    return stem.util._hash_attr(self, 'name', 'size', cache = True)
 
 
 class Address(Field):
@@ -745,7 +706,7 @@ def _unpack_ipv6_address(value):
   return ':'.join(['%04x' % Size.SHORT.unpack(value[i * 2:(i + 1) * 2]) for i in range(8)])
 
 
-setattr(Size, 'CHAR', Size('CHAR', 1, '!B'))
-setattr(Size, 'SHORT', Size('SHORT', 2, '!H'))
-setattr(Size, 'LONG', Size('LONG', 4, '!L'))
-setattr(Size, 'LONG_LONG', Size('LONG_LONG', 8, '!Q'))
+setattr(Size, 'CHAR', Size('CHAR', 1))
+setattr(Size, 'SHORT', Size('SHORT', 2))
+setattr(Size, 'LONG', Size('LONG', 4))
+setattr(Size, 'LONG_LONG', Size('LONG_LONG', 8))
diff --git a/stem/control.py b/stem/control.py
index 56567467..4adec330 100644
--- a/stem/control.py
+++ b/stem/control.py
@@ -253,21 +253,10 @@ import functools
 import inspect
 import io
 import os
+import queue
 import threading
 import time
 
-try:
-  # Added in 2.7
-  from collections import OrderedDict
-except ImportError:
-  from stem.util.ordereddict import OrderedDict
-
-try:
-  # Added in 3.x
-  import queue
-except ImportError:
-  import Queue as queue
-
 import stem.descriptor.microdescriptor
 import stem.descriptor.reader
 import stem.descriptor.router_status_entry
@@ -1166,7 +1155,7 @@ class Controller(BaseController):
     start_time = time.time()
     reply = {}
 
-    if stem.util._is_str(params):
+    if isinstance(params, (bytes, str)):
       is_multiple = False
       params = set([params])
     else:
@@ -1211,7 +1200,7 @@ class Controller(BaseController):
 
       # usually we want unicode values under python 3.x
 
-      if stem.prereq.is_python_3() and not get_bytes:
+      if not get_bytes:
         response.entries = dict((k, stem.util.str_tools._to_unicode(v)) for (k, v) in response.entries.items())
 
       reply.update(response.entries)
@@ -2314,7 +2303,7 @@ class Controller(BaseController):
     start_time = time.time()
     reply = {}
 
-    if stem.util._is_str(params):
+    if isinstance(params, (bytes, str)):
       params = [params]
 
     # remove strings which contain only whitespace
@@ -2623,7 +2612,7 @@ class Controller(BaseController):
       log.debug('GETCONF HiddenServiceOptions (failed: %s)' % exc)
       raise
 
-    service_dir_map = OrderedDict()
+    service_dir_map = collections.OrderedDict()
     directory = None
 
     for status_code, divider, content in response.content():
@@ -2779,7 +2768,7 @@ class Controller(BaseController):
     if path in conf and (port, target_address, target_port) in conf[path]['HiddenServicePort']:
       return None
 
-    conf.setdefault(path, OrderedDict()).setdefault('HiddenServicePort', []).append((port, target_address, target_port))
+    conf.setdefault(path, collections.OrderedDict()).setdefault('HiddenServicePort', []).append((port, target_address, target_port))
 
     if auth_type and client_names:
       hsac = "%s %s" % (auth_type, ','.join(client_names))
@@ -3482,7 +3471,7 @@ class Controller(BaseController):
       * :class:`stem.InvalidArguments` if features passed were invalid
     """
 
-    if stem.util._is_str(features):
+    if isinstance(features, (bytes, str)):
       features = [features]
 
     response = self.msg('USEFEATURE %s' % ' '.join(features))
@@ -3637,7 +3626,7 @@ class Controller(BaseController):
 
       args = [circuit_id]
 
-      if stem.util._is_str(path):
+      if isinstance(path, (bytes, str)):
         path = [path]
 
       if path:
diff --git a/stem/descriptor/__init__.py b/stem/descriptor/__init__.py
index c97db183..fff08910 100644
--- a/stem/descriptor/__init__.py
+++ b/stem/descriptor/__init__.py
@@ -106,12 +106,6 @@ import stem.util.enum
 import stem.util.str_tools
 import stem.util.system
 
-try:
-  # added in python 2.7
-  from collections import OrderedDict
-except ImportError:
-  from stem.util.ordereddict import OrderedDict
-
 __all__ = [
   'bandwidth_file',
   'certificate',
@@ -363,7 +357,7 @@ def parse_file(descriptor_file, descriptor_type = None, validate = False, docume
 
   handler = None
 
-  if stem.util._is_str(descriptor_file):
+  if isinstance(descriptor_file, (bytes, str)):
     if stem.util.system.is_tarfile(descriptor_file):
       handler = _parse_file_for_tar_path
     else:
@@ -377,14 +371,7 @@ def parse_file(descriptor_file, descriptor_type = None, validate = False, docume
 
     return
 
-  # Not all files are seekable. If unseekable then advising the user.
-  #
-  # Python 3.x adds an io.seekable() method, but not an option with python 2.x
-  # so using an experimental call to tell() to determine this.
-
-  try:
-    descriptor_file.tell()
-  except IOError:
+  if not descriptor_file.seekable():
     raise IOError(UNSEEKABLE_MSG)
 
   # The tor descriptor specifications do not provide a reliable method for
@@ -453,16 +440,10 @@ def _parse_file_for_path(descriptor_file, *args, **kwargs):
 
 
 def _parse_file_for_tar_path(descriptor_file, *args, **kwargs):
-  # TODO: use 'with' for tarfile after dropping python 2.6 support
-  tar_file = tarfile.open(descriptor_file)
-
-  try:
+  with tarfile.open(descriptor_file) as tar_file:
     for desc in parse_file(tar_file, *args, **kwargs):
       desc._set_path(os.path.abspath(descriptor_file))
       yield desc
-  finally:
-    if tar_file:
-      tar_file.close()
 
 
 def _parse_file_for_tarfile(descriptor_file, *args, **kwargs):
@@ -589,7 +570,7 @@ def _descriptor_content(attr = None, exclude = (), header_template = (), footer_
   """
 
   header_content, footer_content = [], []
-  attr = {} if attr is None else OrderedDict(attr)  # shallow copy since we're destructive
+  attr = {} if attr is None else collections.OrderedDict(attr)  # shallow copy since we're destructive
 
   for content, template in ((header_content, header_template),
                             (footer_content, footer_template)):
@@ -707,7 +688,7 @@ def _parse_protocol_line(keyword, attribute):
     # parses 'protocol' entries like: Cons=1-2 Desc=1-2 DirCache=1 HSDir=1
 
     value = _value(keyword, entries)
-    protocols = OrderedDict()
+    protocols = collections.OrderedDict()
 
     for k, v in _mappings_for(keyword, value):
       versions = []
@@ -1163,10 +1144,7 @@ class Descriptor(object):
     return super(Descriptor, self).__getattribute__(name)
 
   def __str__(self):
-    if stem.prereq.is_python_3():
-      return stem.util.str_tools._to_unicode(self._raw_contents)
-    else:
-      return self._raw_contents
+    return stem.util.str_tools._to_unicode(self._raw_contents)
 
   def _compare(self, other, method):
     if type(self) != type(other):
@@ -1240,7 +1218,7 @@ def _read_until_keywords(keywords, descriptor_file, inclusive = False, ignore_fi
   content = None if skip else []
   ending_keyword = None
 
-  if stem.util._is_str(keywords):
+  if isinstance(keywords, (bytes, str)):
     keywords = (keywords,)
 
   if ignore_first:
@@ -1468,7 +1446,7 @@ def _descriptor_components(raw_contents, validate, extra_keywords = (), non_asci
   if isinstance(raw_contents, bytes):
     raw_contents = stem.util.str_tools._to_unicode(raw_contents)
 
-  entries = OrderedDict()
+  entries = collections.OrderedDict()
   extra_entries = []  # entries with a keyword in extra_keywords
   remaining_lines = raw_contents.split('\n')
 
diff --git a/stem/descriptor/bandwidth_file.py b/stem/descriptor/bandwidth_file.py
index 658f02b8..43c43aff 100644
--- a/stem/descriptor/bandwidth_file.py
+++ b/stem/descriptor/bandwidth_file.py
@@ -14,6 +14,7 @@ Parsing for Bandwidth Authority metrics as described in Tor's
 .. versionadded:: 1.8.0
 """
 
+import collections
 import datetime
 import io
 import time
@@ -25,12 +26,6 @@ from stem.descriptor import (
   Descriptor,
 )
 
-try:
-  # added in python 2.7
-  from collections import OrderedDict
-except ImportError:
-  from stem.util.ordereddict import OrderedDict
-
 # Four character dividers are allowed for backward compatability, but five is
 # preferred.
 
@@ -175,7 +170,7 @@ def _parse_file(descriptor_file, validate = False, **kwargs):
 
 
 def _parse_header(descriptor, entries):
-  header = OrderedDict()
+  header = collections.OrderedDict()
   content = io.BytesIO(descriptor.get_bytes())
 
   content.readline()  # skip the first line, which should be the timestamp
@@ -332,7 +327,7 @@ class BandwidthFile(Descriptor):
     if sign:
       raise NotImplementedError('Signing of %s not implemented' % cls.__name__)
 
-    header = OrderedDict(attr) if attr is not None else OrderedDict()
+    header = collections.OrderedDict(attr) if attr is not None else collections.OrderedDict()
     timestamp = header.pop('timestamp', str(int(time.time())))
     content = header.pop('content', [])
     version = header.get('version', HEADER_DEFAULT.get('version'))
diff --git a/stem/descriptor/collector.py b/stem/descriptor/collector.py
index c2bf8179..7aeb298b 100644
--- a/stem/descriptor/collector.py
+++ b/stem/descriptor/collector.py
@@ -55,7 +55,6 @@ import hashlib
 import json
 import os
 import re
-import shutil
 import tempfile
 import time
 
@@ -264,15 +263,9 @@ class File(object):
       if self._downloaded_to and os.path.exists(self._downloaded_to):
         directory = os.path.dirname(self._downloaded_to)
       else:
-        # TODO: The following can be replaced with simpler usage of
-        # tempfile.TemporaryDirectory when we drop python 2.x support.
-
-        tmp_directory = tempfile.mkdtemp()
-
-        for desc in self.read(tmp_directory, descriptor_type, start, end, document_handler, timeout, retries):
-          yield desc
-
-        shutil.rmtree(tmp_directory)
+        with tempfile.TemporaryDirectory() as tmp_directory:
+          for desc in self.read(tmp_directory, descriptor_type, start, end, document_handler, timeout, retries):
+            yield desc
 
         return
 
diff --git a/stem/descriptor/export.py b/stem/descriptor/export.py
index 48699ca4..35835d7c 100644
--- a/stem/descriptor/export.py
+++ b/stem/descriptor/export.py
@@ -17,13 +17,9 @@ Toolkit for exporting descriptors to other formats.
    use this modle please `let me know <https://www.atagar.com/contact/>`_.
 """
 
+import io
 import csv
 
-try:
-  from cStringIO import StringIO
-except ImportError:
-  from io import StringIO
-
 import stem.descriptor
 import stem.prereq
 
@@ -44,13 +40,13 @@ def export_csv(descriptors, included_fields = (), excluded_fields = (), header =
   :param list included_fields: attributes to include in the csv
   :param list excluded_fields: attributes to exclude from the csv
   :param bool header: if **True** then the first line will be a comma separated
-    list of the attribute names (**only supported in python 2.7 and higher**)
+    list of the attribute names
 
   :returns: **str** of the CSV for the descriptors, one per line
   :raises: **ValueError** if descriptors contain more than one descriptor type
   """
 
-  output_buffer = StringIO()
+  output_buffer = io.StringIO()
   export_csv_file(output_buffer, descriptors, included_fields, excluded_fields, header)
   return output_buffer.getvalue()
 
@@ -66,7 +62,7 @@ def export_csv_file(output_file, descriptors, included_fields = (), excluded_fie
   :param list included_fields: attributes to include in the csv
   :param list excluded_fields: attributes to exclude from the csv
   :param bool header: if **True** then the first line will be a comma separated
-    list of the attribute names (**only supported in python 2.7 and higher**)
+    list of the attribute names
 
   :returns: **str** of the CSV for the descriptors, one per line
   :raises: **ValueError** if descriptors contain more than one descriptor type
@@ -103,7 +99,7 @@ def export_csv_file(output_file, descriptors, included_fields = (), excluded_fie
 
   writer = csv.DictWriter(output_file, included_fields, dialect = _ExportDialect(), extrasaction='ignore')
 
-  if header and not stem.prereq._is_python_26():
+  if header:
     writer.writeheader()
 
   for desc in descriptors:
diff --git a/stem/descriptor/extrainfo_descriptor.py b/stem/descriptor/extrainfo_descriptor.py
index 17082f88..f53d9502 100644
--- a/stem/descriptor/extrainfo_descriptor.py
+++ b/stem/descriptor/extrainfo_descriptor.py
@@ -100,11 +100,6 @@ from stem.descriptor import (
   _random_crypto_blob,
 )
 
-if stem.prereq._is_lru_cache_available():
-  from functools import lru_cache
-else:
-  from stem.util.lru_cache import lru_cache
-
 # known statuses for dirreq-v2-resp and dirreq-v3-resp...
 DirResponse = stem.util.enum.Enum(
   ('OK', 'ok'),
@@ -950,7 +945,7 @@ class RelayExtraInfoDescriptor(ExtraInfoDescriptor):
   def create(cls, attr = None, exclude = (), validate = True, sign = False, signing_key = None):
     return cls(cls.content(attr, exclude, sign, signing_key), validate = validate)
 
-  @lru_cache()
+  @functools.lru_cache()
   def digest(self, hash_type = DigestHash.SHA1, encoding = DigestEncoding.HEX):
     if hash_type == DigestHash.SHA1:
       # our digest is calculated from everything except our signature
diff --git a/stem/descriptor/hidden_service.py b/stem/descriptor/hidden_service.py
index e5f82861..7994bffb 100644
--- a/stem/descriptor/hidden_service.py
+++ b/stem/descriptor/hidden_service.py
@@ -35,6 +35,7 @@ import base64
 import binascii
 import collections
 import datetime
+import functools
 import hashlib
 import io
 import os
@@ -70,11 +71,6 @@ from stem.descriptor import (
   _random_crypto_blob,
 )
 
-if stem.prereq._is_lru_cache_available():
-  from functools import lru_cache
-else:
-  from stem.util.lru_cache import lru_cache
-
 try:
   from cryptography.hazmat.backends.openssl.backend import backend
   X25519_AVAILABLE = hasattr(backend, 'x25519_supported') and backend.x25519_supported()
@@ -745,7 +741,7 @@ class HiddenServiceDescriptorV2(BaseHiddenServiceDescriptor):
     else:
       self._entries = entries
 
-  @lru_cache()
+  @functools.lru_cache()
   def introduction_points(self, authentication_cookie = None):
     """
     Provided this service's introduction points.
diff --git a/stem/descriptor/microdescriptor.py b/stem/descriptor/microdescriptor.py
index 81bcb43c..17d06d90 100644
--- a/stem/descriptor/microdescriptor.py
+++ b/stem/descriptor/microdescriptor.py
@@ -64,6 +64,7 @@ Doing the same is trivial with server descriptors...
   Microdescriptor - Tor microdescriptor.
 """
 
+import functools
 import hashlib
 
 import stem.exit_policy
@@ -88,11 +89,6 @@ from stem.descriptor.router_status_entry import (
   _parse_p_line,
 )
 
-if stem.prereq._is_lru_cache_available():
-  from functools import lru_cache
-else:
-  from stem.util.lru_cache import lru_cache
-
 REQUIRED_FIELDS = (
   'onion-key',
 )
@@ -305,7 +301,7 @@ class Microdescriptor(Descriptor):
     else:
       raise NotImplementedError('Microdescriptor digests are only available in sha1 and sha256, not %s' % hash_type)
 
-  @lru_cache()
+  @functools.lru_cache()
   def get_annotations(self):
     """
     Provides content that appeared prior to the descriptor. If this comes from
diff --git a/stem/descriptor/reader.py b/stem/descriptor/reader.py
index b4cc4279..e75cdb7e 100644
--- a/stem/descriptor/reader.py
+++ b/stem/descriptor/reader.py
@@ -84,14 +84,10 @@ and picks up where it left off if run again...
 
 import mimetypes
 import os
+import queue
 import tarfile
 import threading
 
-try:
-  import queue
-except ImportError:
-  import Queue as queue
-
 import stem.descriptor
 import stem.prereq
 import stem.util
@@ -259,7 +255,7 @@ class DescriptorReader(object):
   :param bool validate: checks the validity of the descriptor's content if
     **True**, skips these checks otherwise
   :param bool follow_links: determines if we'll follow symlinks when traversing
-    directories (requires python 2.6)
+    directories
   :param int buffer_size: descriptors we'll buffer before waiting for some to
     be read, this is unbounded if zero
   :param str persistence_path: if set we will load and save processed file
@@ -270,7 +266,7 @@ class DescriptorReader(object):
   """
 
   def __init__(self, target, validate = False, follow_links = False, buffer_size = 100, persistence_path = None, document_handler = stem.descriptor.DocumentHandler.ENTRIES, **kwargs):
-    self._targets = [target] if stem.util._is_str(target) else target
+    self._targets = [target] if isinstance(target, (bytes, str)) else target
 
     # expand any relative paths we got
 
@@ -525,41 +521,31 @@ class DescriptorReader(object):
       self._notify_skip_listeners(target, ReadFailed(exc))
 
   def _handle_archive(self, target):
-    # TODO: When dropping python 2.6 support go back to using 'with' for
-    # tarfiles...
-    #
-    #   http://bugs.python.org/issue7232
-
-    tar_file = None
-
     try:
-      self._notify_read_listeners(target)
-      tar_file = tarfile.open(target)
-
-      for tar_entry in tar_file:
-        if tar_entry.isfile():
-          entry = tar_file.extractfile(tar_entry)
-
-          try:
-            for desc in stem.descriptor.parse_file(entry, validate = self._validate, document_handler = self._document_handler, **self._kwargs):
-              if self._is_stopped.is_set():
-                return
-
-              desc._set_path(os.path.abspath(target))
-              desc._set_archive_path(tar_entry.name)
-              self._unreturned_descriptors.put(desc)
-              self._iter_notice.set()
-          except TypeError as exc:
-            self._notify_skip_listeners(target, ParsingFailure(exc))
-          except ValueError as exc:
-            self._notify_skip_listeners(target, ParsingFailure(exc))
-          finally:
-            entry.close()
+      with tarfile.open(target) as tar_file:
+        self._notify_read_listeners(target)
+
+        for tar_entry in tar_file:
+          if tar_entry.isfile():
+            entry = tar_file.extractfile(tar_entry)
+
+            try:
+              for desc in stem.descriptor.parse_file(entry, validate = self._validate, document_handler = self._document_handler, **self._kwargs):
+                if self._is_stopped.is_set():
+                  return
+
+                desc._set_path(os.path.abspath(target))
+                desc._set_archive_path(tar_entry.name)
+                self._unreturned_descriptors.put(desc)
+                self._iter_notice.set()
+            except TypeError as exc:
+              self._notify_skip_listeners(target, ParsingFailure(exc))
+            except ValueError as exc:
+              self._notify_skip_listeners(target, ParsingFailure(exc))
+            finally:
+              entry.close()
     except IOError as exc:
       self._notify_skip_listeners(target, ReadFailed(exc))
-    finally:
-      if tar_file:
-        tar_file.close()
 
   def _notify_read_listeners(self, path):
     for listener in self._read_listeners:
diff --git a/stem/descriptor/remote.py b/stem/descriptor/remote.py
index c88b338e..c7132a38 100644
--- a/stem/descriptor/remote.py
+++ b/stem/descriptor/remote.py
@@ -104,6 +104,7 @@ import socket
 import sys
 import threading
 import time
+import urllib.request
 
 import stem
 import stem.client
@@ -116,12 +117,6 @@ import stem.util.tor_tools
 
 from stem.util import log, str_tools
 
-try:
-  # account for urllib's change between python 2.x and 3.x
-  import urllib.request as urllib
-except ImportError:
-  import urllib2 as urllib
-
 # TODO: remove in stem 2.x, replaced with stem.descriptor.Compression
 
 Compression = stem.util.enum.Enum(
@@ -1070,8 +1065,8 @@ def _download_from_dirport(url, compression, timeout):
   """
 
   try:
-    response = urllib.urlopen(
-      urllib.Request(
+    response = urllib.request.urlopen(
+      urllib.request.Request(
         url,
         headers = {
           'Accept-Encoding': ', '.join(map(lambda c: c.encoding, compression)),
diff --git a/stem/descriptor/router_status_entry.py b/stem/descriptor/router_status_entry.py
index cf1c52f5..d248774a 100644
--- a/stem/descriptor/router_status_entry.py
+++ b/stem/descriptor/router_status_entry.py
@@ -374,9 +374,7 @@ def _base64_to_hex(identity, check_if_fingerprint = True):
     raise ValueError("Unable to decode identity string '%s'" % identity)
 
   fingerprint = binascii.hexlify(identity_decoded).upper()
-
-  if stem.prereq.is_python_3():
-    fingerprint = stem.util.str_tools._to_unicode(fingerprint)
+  fingerprint = stem.util.str_tools._to_unicode(fingerprint)
 
   if check_if_fingerprint:
     if not stem.util.tor_tools.is_valid_fingerprint(fingerprint):
diff --git a/stem/descriptor/server_descriptor.py b/stem/descriptor/server_descriptor.py
index 1d9adf32..84ba8b65 100644
--- a/stem/descriptor/server_descriptor.py
+++ b/stem/descriptor/server_descriptor.py
@@ -92,11 +92,6 @@ from stem.descriptor import (
   _random_crypto_blob,
 )
 
-if stem.prereq._is_lru_cache_available():
-  from functools import lru_cache
-else:
-  from stem.util.lru_cache import lru_cache
-
 # relay descriptors must have exactly one of the following
 REQUIRED_FIELDS = (
   'router',
@@ -668,7 +663,7 @@ class ServerDescriptor(Descriptor):
 
     raise NotImplementedError('Unsupported Operation: this should be implemented by the ServerDescriptor subclass')
 
-  @lru_cache()
+  @functools.lru_cache()
   def get_annotations(self):
     """
     Provides content that appeared prior to the descriptor. If this comes from
@@ -910,7 +905,7 @@ class RelayDescriptor(ServerDescriptor):
   def create(cls, attr = None, exclude = (), validate = True, sign = False, signing_key = None, exit_policy = None):
     return cls(cls.content(attr, exclude, sign, signing_key, exit_policy), validate = validate, skip_crypto_validation = not sign)
 
-  @lru_cache()
+  @functools.lru_cache()
   def digest(self, hash_type = DigestHash.SHA1, encoding = DigestEncoding.HEX):
     """
     Provides the digest of our descriptor's content.
@@ -967,7 +962,7 @@ class RelayDescriptor(ServerDescriptor):
 
     return RouterStatusEntryV3.create(attr)
 
-  @lru_cache()
+  @functools.lru_cache()
   def _onion_key_crosscert_digest(self):
     """
     Provides the digest of the onion-key-crosscert data. This consists of the
@@ -1051,7 +1046,7 @@ class BridgeDescriptor(ServerDescriptor):
 
     return self.get_scrubbing_issues() == []
 
-  @lru_cache()
+  @functools.lru_cache()
   def get_scrubbing_issues(self):
     """
     Provides issues with our scrubbing.
diff --git a/stem/directory.py b/stem/directory.py
index b93b49a2..7a1ce7b8 100644
--- a/stem/directory.py
+++ b/stem/directory.py
@@ -38,9 +38,11 @@ as follows...
 .. versionadded:: 1.7.0
 """
 
+import collections
 import os
 import re
 import sys
+import urllib.request
 
 import stem
 import stem.util
@@ -48,18 +50,6 @@ import stem.util.conf
 
 from stem.util import connection, str_tools, tor_tools
 
-try:
-  # added in python 2.7
-  from collections import OrderedDict
-except ImportError:
-  from stem.util.ordereddict import OrderedDict
-
-try:
-  # account for urllib's change between python 2.x and 3.x
-  import urllib.request as urllib
-except ImportError:
-  import urllib2 as urllib
-
 GITWEB_AUTHORITY_URL = 'https://gitweb.torproject.org/tor.git/plain/src/app/config/auth_dirs.inc'
 GITWEB_FALLBACK_URL = 'https://gitweb.torproject.org/tor.git/plain/src/app/config/fallback_dirs.inc'
 FALLBACK_CACHE_PATH = os.path.join(os.path.dirname(__file__), 'cached_fallbacks.cfg')
@@ -265,7 +255,7 @@ class Authority(Directory):
   @staticmethod
   def from_remote(timeout = 60):
     try:
-      lines = str_tools._to_unicode(urllib.urlopen(GITWEB_AUTHORITY_URL, timeout = timeout).read()).splitlines()
+      lines = str_tools._to_unicode(urllib.request.urlopen(GITWEB_AUTHORITY_URL, timeout = timeout).read()).splitlines()
 
       if not lines:
         raise IOError('no content')
@@ -369,13 +359,13 @@ class Fallback(Directory):
   def __init__(self, address = None, or_port = None, dir_port = None, fingerprint = None, nickname = None, has_extrainfo = False, orport_v6 = None, header = None):
     super(Fallback, self).__init__(address, or_port, dir_port, fingerprint, nickname, orport_v6)
     self.has_extrainfo = has_extrainfo
-    self.header = OrderedDict(header) if header else OrderedDict()
+    self.header = collections.OrderedDict(header) if header else collections.OrderedDict()
 
   @staticmethod
   def from_cache(path = FALLBACK_CACHE_PATH):
     conf = stem.util.conf.Config()
     conf.load(path)
-    headers = OrderedDict([(k.split('.', 1)[1], conf.get(k)) for k in conf.keys() if k.startswith('header.')])
+    headers = collections.OrderedDict([(k.split('.', 1)[1], conf.get(k)) for k in conf.keys() if k.startswith('header.')])
 
     results = {}
 
@@ -413,7 +403,7 @@ class Fallback(Directory):
   @staticmethod
   def from_remote(timeout = 60):
     try:
-      lines = str_tools._to_unicode(urllib.urlopen(GITWEB_FALLBACK_URL, timeout = timeout).read()).splitlines()
+      lines = str_tools._to_unicode(urllib.request.urlopen(GITWEB_FALLBACK_URL, timeout = timeout).read()).splitlines()
 
       if not lines:
         raise IOError('no content')
diff --git a/stem/exit_policy.py b/stem/exit_policy.py
index ddaf719c..0d1e7e42 100644
--- a/stem/exit_policy.py
+++ b/stem/exit_policy.py
@@ -67,6 +67,7 @@ exiting to a destination is permissible or not. For instance...
 
 from __future__ import absolute_import
 
+import functools
 import re
 import socket
 import zlib
@@ -77,11 +78,6 @@ import stem.util.connection
 import stem.util.enum
 import stem.util.str_tools
 
-if stem.prereq._is_lru_cache_available():
-  from functools import lru_cache
-else:
-  from stem.util.lru_cache import lru_cache
-
 AddressType = stem.util.enum.Enum(('WILDCARD', 'Wildcard'), ('IPv4', 'IPv4'), ('IPv6', 'IPv6'))
 
 # Addresses aliased by the 'private' policy. From the tor man page...
@@ -128,7 +124,7 @@ def get_config_policy(rules, ip_address = None):
   elif ip_address and stem.util.connection.is_valid_ipv6_address(ip_address, allow_brackets = True) and not (ip_address[0] == '[' and ip_address[-1] == ']'):
     ip_address = '[%s]' % ip_address  # ExitPolicy validation expects IPv6 addresses to be bracketed
 
-  if stem.util._is_str(rules):
+  if isinstance(rules, (bytes, str)):
     rules = rules.split(',')
 
   result = []
@@ -242,7 +238,7 @@ class ExitPolicy(object):
     # sanity check the types
 
     for rule in rules:
-      if not stem.util._is_str(rule) and not isinstance(rule, ExitPolicyRule):
+      if not isinstance(rule, (bytes, str)) and not isinstance(rule, ExitPolicyRule):
         raise TypeError('Exit policy rules can only contain strings or ExitPolicyRules, got a %s (%s)' % (type(rule), rules))
 
     # Unparsed representation of the rules we were constructed with. Our
@@ -253,7 +249,7 @@ class ExitPolicy(object):
     is_all_str = True
 
     for rule in rules:
-      if not stem.util._is_str(rule):
+      if not isinstance(rule, (bytes, str)):
         is_all_str = False
 
     if rules and is_all_str:
@@ -271,7 +267,7 @@ class ExitPolicy(object):
 
     self._is_allowed_default = True
 
-  @lru_cache()
+  @functools.lru_cache()
   def can_exit_to(self, address = None, port = None, strict = False):
     """
     Checks if this policy allows exiting to a given destination or not. If the
@@ -295,7 +291,7 @@ class ExitPolicy(object):
 
     return self._is_allowed_default
 
-  @lru_cache()
+  @functools.lru_cache()
   def is_exiting_allowed(self):
     """
     Provides **True** if the policy allows exiting whatsoever, **False**
@@ -317,7 +313,7 @@ class ExitPolicy(object):
 
     return self._is_allowed_default
 
-  @lru_cache()
+  @functools.lru_cache()
   def summary(self):
     """
     Provides a short description of our policy chain, similar to a
@@ -470,7 +466,7 @@ class ExitPolicy(object):
         if isinstance(rule, bytes):
           rule = stem.util.str_tools._to_unicode(rule)
 
-        if stem.util._is_str(rule):
+        if isinstance(rule, (bytes, str)):
           if not rule.strip():
             continue
 
@@ -520,7 +516,7 @@ class ExitPolicy(object):
     for rule in self._get_rules():
       yield rule
 
-  @lru_cache()
+  @functools.lru_cache()
   def __str__(self):
     return ', '.join([str(rule) for rule in self._get_rules()])
 
@@ -873,7 +869,7 @@ class ExitPolicyRule(object):
 
     return self._is_default_suffix
 
-  @lru_cache()
+  @functools.lru_cache()
   def __str__(self):
     """
     Provides the string representation of our policy. This does not
@@ -917,13 +913,13 @@ class ExitPolicyRule(object):
 
     return label
 
-  @lru_cache()
+  @functools.lru_cache()
   def _get_mask_bin(self):
     # provides an integer representation of our mask
 
     return int(stem.util.connection._address_to_binary(self.get_mask(False)), 2)
 
-  @lru_cache()
+  @functools.lru_cache()
   def _get_address_bin(self):
     # provides an integer representation of our address
 
diff --git a/stem/interpreter/__init__.py b/stem/interpreter/__init__.py
index 30af3f62..67984261 100644
--- a/stem/interpreter/__init__.py
+++ b/stem/interpreter/__init__.py
@@ -127,14 +127,7 @@ def main():
 
     if args.run_cmd:
       if args.run_cmd.upper().startswith('SETEVENTS '):
-        # TODO: we can use a lambda here when dropping python 2.x support, but
-        # until then print's status as a keyword prevents it from being used in
-        # lambdas
-
-        def handle_event(event_message):
-          print(format(str(event_message), *STANDARD_OUTPUT))
-
-        controller._handle_event = handle_event
+        controller._handle_event = lambda event_message: print(format(str(event_message), *STANDARD_OUTPUT))
 
         if sys.stdout.isatty():
           events = args.run_cmd.upper().split(' ', 1)[1]
@@ -171,14 +164,14 @@ def main():
       while True:
         try:
           prompt = '... ' if interpreter.is_multiline_context else PROMPT
-          user_input = input(prompt) if stem.prereq.is_python_3() else raw_input(prompt)
+          user_input = input(prompt)
           interpreter.run_command(user_input, print_response = True)
         except stem.SocketClosed:
           if showed_close_confirmation:
             print(format('Unable to run tor commands. The control connection has been closed.', *ERROR_OUTPUT))
           else:
             prompt = format("Tor's control port has closed. Do you want to continue this interpreter? (y/n) ", *HEADER_BOLD_OUTPUT)
-            user_input = input(prompt) if stem.prereq.is_python_3() else raw_input(prompt)
+            user_input = input(prompt)
             print('')  # blank line
 
             if user_input.lower() in ('y', 'yes'):
diff --git a/stem/interpreter/autocomplete.py b/stem/interpreter/autocomplete.py
index b6c5354c..05585b48 100644
--- a/stem/interpreter/autocomplete.py
+++ b/stem/interpreter/autocomplete.py
@@ -5,15 +5,12 @@
 Tab completion for our interpreter prompt.
 """
 
+import functools
+
 import stem.prereq
 
 from stem.interpreter import uses_settings
 
-if stem.prereq._is_lru_cache_available():
-  from functools import lru_cache
-else:
-  from stem.util.lru_cache import lru_cache
-
 
 @uses_settings
 def _get_commands(controller, config):
@@ -84,7 +81,7 @@ class Autocompleter(object):
   def __init__(self, controller):
     self._commands = _get_commands(controller)
 
-  @lru_cache()
+  @functools.lru_cache()
   def matches(self, text):
     """
     Provides autocompletion matches for the given text.
diff --git a/stem/interpreter/commands.py b/stem/interpreter/commands.py
index 0f8f333c..6e61fdda 100644
--- a/stem/interpreter/commands.py
+++ b/stem/interpreter/commands.py
@@ -7,6 +7,7 @@ Handles making requests and formatting the responses.
 
 import code
 import contextlib
+import io
 import socket
 import sys
 
@@ -21,11 +22,6 @@ import stem.util.tor_tools
 from stem.interpreter import STANDARD_OUTPUT, BOLD_OUTPUT, ERROR_OUTPUT, uses_settings, msg
 from stem.util.term import format
 
-try:
-  from cStringIO import StringIO
-except ImportError:
-  from io import StringIO
-
 MAX_EVENTS = 100
 
 
@@ -359,7 +355,7 @@ class ControlInterpreter(code.InteractiveConsole):
         is_tor_command = cmd in config.get('help.usage', {}) and cmd.lower() != 'events'
 
         if self._run_python_commands and not is_tor_command:
-          console_output = StringIO()
+          console_output = io.StringIO()
 
           with redirect(console_output, console_output):
             self.is_multiline_context = code.InteractiveConsole.push(self, command)
diff --git a/stem/interpreter/help.py b/stem/interpreter/help.py
index d2e08d5c..5fde9246 100644
--- a/stem/interpreter/help.py
+++ b/stem/interpreter/help.py
@@ -5,6 +5,8 @@
 Provides our /help responses.
 """
 
+import functools
+
 import stem.prereq
 
 from stem.interpreter import (
@@ -17,11 +19,6 @@ from stem.interpreter import (
 
 from stem.util.term import format
 
-if stem.prereq._is_lru_cache_available():
-  from functools import lru_cache
-else:
-  from stem.util.lru_cache import lru_cache
-
 
 def response(controller, arg):
   """
@@ -55,7 +52,7 @@ def _normalize(arg):
   return arg
 
 
-@lru_cache()
+@functools.lru_cache()
 @uses_settings
 def _response(controller, arg, config):
   if not arg:
diff --git a/stem/manual.py b/stem/manual.py
index 25d435d4..c1b4bd8f 100644
--- a/stem/manual.py
+++ b/stem/manual.py
@@ -48,10 +48,13 @@ us what our torrc options do...
 .. versionadded:: 1.5.0
 """
 
+import collections
+import functools
 import os
 import shutil
 import sys
 import tempfile
+import urllib.request
 
 import stem
 import stem.prereq
@@ -61,23 +64,6 @@ import stem.util.enum
 import stem.util.log
 import stem.util.system
 
-try:
-  # added in python 2.7
-  from collections import OrderedDict
-except ImportError:
-  from stem.util.ordereddict import OrderedDict
-
-if stem.prereq._is_lru_cache_available():
-  from functools import lru_cache
-else:
-  from stem.util.lru_cache import lru_cache
-
-try:
-  # account for urllib's change between python 2.x and 3.x
-  import urllib.request as urllib
-except ImportError:
-  import urllib2 as urllib
-
 Category = stem.util.enum.Enum('GENERAL', 'CLIENT', 'RELAY', 'DIRECTORY', 'AUTHORITY', 'HIDDEN_SERVICE', 'DENIAL_OF_SERVICE', 'TESTING', 'UNKNOWN')
 GITWEB_MANUAL_URL = 'https://gitweb.torproject.org/tor.git/plain/doc/tor.1.txt'
 CACHE_PATH = os.path.join(os.path.dirname(__file__), 'cached_manual.sqlite')
@@ -96,7 +82,7 @@ SCHEMA = (
   'CREATE TABLE torrc(key TEXT PRIMARY KEY, name TEXT, category TEXT, usage TEXT, summary TEXT, description TEXT, position INTEGER)',
 )
 
-CATEGORY_SECTIONS = OrderedDict((
+CATEGORY_SECTIONS = collections.OrderedDict((
   ('GENERAL OPTIONS', Category.GENERAL),
   ('CLIENT OPTIONS', Category.CLIENT),
   ('SERVER OPTIONS', Category.RELAY),
@@ -199,7 +185,7 @@ class ConfigOption(object):
     return not self == other
 
 
-@lru_cache()
+@functools.lru_cache()
 def _config(lowercase = True):
   """
   Provides a dictionary for our settings.cfg. This has a couple categories...
@@ -302,14 +288,13 @@ def download_man_page(path = None, file_handle = None, url = GITWEB_MANUAL_URL,
   elif not stem.util.system.is_available('a2x'):
     raise IOError('We require a2x from asciidoc to provide a man page')
 
-  dirpath = tempfile.mkdtemp()
-  asciidoc_path = os.path.join(dirpath, 'tor.1.txt')
-  manual_path = os.path.join(dirpath, 'tor.1')
+  with tempfile.TemporaryDirectory() as dirpath:
+    asciidoc_path = os.path.join(dirpath, 'tor.1.txt')
+    manual_path = os.path.join(dirpath, 'tor.1')
 
-  try:
     try:
       with open(asciidoc_path, 'wb') as asciidoc_file:
-        request = urllib.urlopen(url, timeout = timeout)
+        request = urllib.request.urlopen(url, timeout = timeout)
         shutil.copyfileobj(request, asciidoc_file)
     except:
       exc, stacktrace = sys.exc_info()[1:3]
@@ -339,8 +324,6 @@ def download_man_page(path = None, file_handle = None, url = GITWEB_MANUAL_URL,
       with open(manual_path, 'rb') as manual_file:
         shutil.copyfileobj(manual_file, file_handle)
         file_handle.flush()
-  finally:
-    shutil.rmtree(dirpath)
 
 
 class Manual(object):
@@ -374,10 +357,10 @@ class Manual(object):
     self.name = name
     self.synopsis = synopsis
     self.description = description
-    self.commandline_options = OrderedDict(commandline_options)
-    self.signals = OrderedDict(signals)
-    self.files = OrderedDict(files)
-    self.config_options = OrderedDict(config_options)
+    self.commandline_options = collections.OrderedDict(commandline_options)
+    self.signals = collections.OrderedDict(signals)
+    self.files = collections.OrderedDict(files)
+    self.config_options = collections.OrderedDict(config_options)
     self.man_commit = None
     self.stem_commit = None
     self.schema = None
@@ -442,7 +425,7 @@ class Manual(object):
       signals = dict(conn.execute('SELECT name, description FROM signals').fetchall())
       files = dict(conn.execute('SELECT name, description FROM files').fetchall())
 
-      config_options = OrderedDict()
+      config_options = collections.OrderedDict()
 
       for entry in conn.execute('SELECT name, category, usage, summary, description FROM torrc ORDER BY position').fetchall():
         option, category, usage, summary, option_description = entry
@@ -460,7 +443,7 @@ class Manual(object):
     conf = stem.util.conf.Config()
     conf.load(path, commenting = False)
 
-    config_options = OrderedDict()
+    config_options = collections.OrderedDict()
 
     for key in conf.keys():
       if key.startswith('config_options.'):
@@ -479,9 +462,9 @@ class Manual(object):
       conf.get('name', ''),
       conf.get('synopsis', ''),
       conf.get('description', ''),
-      conf.get('commandline_options', OrderedDict()),
-      conf.get('signals', OrderedDict()),
-      conf.get('files', OrderedDict()),
+      conf.get('commandline_options', collections.OrderedDict()),
+      conf.get('signals', collections.OrderedDict()),
+      conf.get('files', collections.OrderedDict()),
       config_options,
     )
 
@@ -514,7 +497,7 @@ class Manual(object):
     except OSError as exc:
       raise IOError("Unable to run '%s': %s" % (man_cmd, exc))
 
-    categories, config_options = _get_categories(man_output), OrderedDict()
+    categories, config_options = _get_categories(man_output), collections.OrderedDict()
 
     for category_header, category_enum in CATEGORY_SECTIONS.items():
       _add_config_options(config_options, category_enum, categories.get(category_header, []))
@@ -677,7 +660,7 @@ def _get_categories(content):
   if content and content[-1].startswith('Tor'):
     content = content[:-1]
 
-  categories = OrderedDict()
+  categories = collections.OrderedDict()
   category, lines = None, []
 
   for line in content:
@@ -687,8 +670,7 @@ def _get_categories(content):
     #   \u2014 - extra long dash
     #   \xb7 - centered dot
 
-    char_for = chr if stem.prereq.is_python_3() else unichr
-    line = line.replace(char_for(0x2019), "'").replace(char_for(0x2014), '-').replace(char_for(0xb7), '*')
+    line = line.replace(chr(0x2019), "'").replace(chr(0x2014), '-').replace(chr(0xb7), '*')
 
     if line and not line.startswith(' '):
       if category:
@@ -727,7 +709,7 @@ def _get_indented_descriptions(lines):
   ignoring those.
   """
 
-  options, last_arg = OrderedDict(), None
+  options, last_arg = collections.OrderedDict(), None
 
   for line in lines:
     if line == '    Note':
diff --git a/stem/prereq.py b/stem/prereq.py
index 5e8e89dc..74584165 100644
--- a/stem/prereq.py
+++ b/stem/prereq.py
@@ -12,12 +12,10 @@ stem will still read descriptors - just without signature checks.
 ::
 
   check_requirements - checks for minimum requirements for running stem
-  is_python_3 - checks if python 3.0 or later is available
   is_sqlite_available - checks if the sqlite3 module is available
   is_crypto_available - checks if the cryptography module is available
   is_zstd_available - checks if the zstd module is available
   is_lzma_available - checks if the lzma module is available
-  is_mock_available - checks if the mock module is available
 """
 
 import functools
@@ -46,52 +44,8 @@ def check_requirements():
 
   major_version, minor_version = sys.version_info[0:2]
 
-  if major_version < 2 or (major_version == 2 and minor_version < 6):
-    raise ImportError('stem requires python version 2.6 or greater')
-
-
-def _is_python_26():
-  """
-  Checks if we're running python 2.6. This isn't for users as it'll be removed
-  in stem 2.0 (when python 2.6 support goes away).
-
-  .. deprecated:: 1.8.0
-     Stem 2.x will remove this method along with Python 2.x support.
-
-  :returns: **True** if we're running python 2.6, **False** otherwise
-  """
-
-  major_version, minor_version = sys.version_info[0:2]
-
-  return major_version == 2 and minor_version == 6
-
-
-def is_python_27():
-  """
-  Checks if we're running python 2.7 or above (including the 3.x series).
-
-  .. deprecated:: 1.5.0
-     Stem 2.x will remove this method along with Python 2.x support.
-
-  :returns: **True** if we meet this requirement and **False** otherwise
-  """
-
-  major_version, minor_version = sys.version_info[0:2]
-
-  return major_version > 2 or (major_version == 2 and minor_version >= 7)
-
-
-def is_python_3():
-  """
-  Checks if we're in the 3.0 - 3.x range.
-
-  .. deprecated:: 1.8.0
-     Stem 2.x will remove this method along with Python 2.x support.
-
-  :returns: **True** if we meet this requirement and **False** otherwise
-  """
-
-  return sys.version_info[0] == 3
+  if major_version < 3 or (major_version == 3 and minor_version < 6):
+    raise ImportError('stem requires python version 3.6 or greater')
 
 
 def is_pypy():
@@ -207,63 +161,6 @@ def is_lzma_available():
     return False
 
 
-def is_mock_available():
-  """
-  Checks if the mock module is available. In python 3.3 and up it is a builtin
-  unittest module, but before this it needed to be `installed separately
-  <https://pypi.org/project/mock/>`_. Imports should be as follows....
-
-  ::
-
-    try:
-      # added in python 3.3
-      from unittest.mock import Mock
-    except ImportError:
-      from mock import Mock
-
-  :returns: **True** if the mock module is available and **False** otherwise
-  """
-
-  try:
-    # checks for python 3.3 version
-    import unittest.mock
-    return True
-  except ImportError:
-    pass
-
-  try:
-    import mock
-
-    # check for mock's patch.dict() which was introduced in version 0.7.0
-
-    if not hasattr(mock.patch, 'dict'):
-      raise ImportError()
-
-    # check for mock's new_callable argument for patch() which was introduced in version 0.8.0
-
-    if 'new_callable' not in inspect.getargspec(mock.patch).args:
-      raise ImportError()
-
-    return True
-  except ImportError:
-    return False
-
-
-def _is_lru_cache_available():
-  """
-  Functools added lru_cache to the standard library in Python 3.2. Prior to
-  this using a bundled implementation. We're also using this with Python 3.5
-  due to a buggy implementation. (:trac:`26412`)
-  """
-
-  major_version, minor_version = sys.version_info[0:2]
-
-  if major_version == 3 and minor_version == 5:
-    return False
-  else:
-    return hasattr(functools, 'lru_cache')
-
-
 def _is_sha3_available():
   """
   Check if hashlib has sha3 support. This requires Python 3.6+ *or* the `pysha3
diff --git a/stem/process.py b/stem/process.py
index 4ed10dfb..3f1a0e19 100644
--- a/stem/process.py
+++ b/stem/process.py
@@ -143,12 +143,9 @@ def launch_tor(tor_cmd = 'tor', args = None, torrc_path = None, completion_perce
     last_problem = 'Timed out'
 
     while True:
-      # Tor's stdout will be read as ASCII bytes. This is fine for python 2, but
-      # in python 3 that means it'll mismatch with other operations (for instance
-      # the bootstrap_line.search() call later will fail).
-      #
-      # It seems like python 2.x is perfectly happy for this to be unicode, so
-      # normalizing to that.
+      # Tor's stdout will be read as ASCII bytes. That means it'll mismatch
+      # with other operations (for instance the bootstrap_line.search() call
+      # later will fail), so normalizing to unicode.
 
       init_line = tor_process.stdout.readline().decode('utf-8', 'replace').strip()
 
diff --git a/stem/response/__init__.py b/stem/response/__init__.py
index 1a5b2b45..2fbb9c48 100644
--- a/stem/response/__init__.py
+++ b/stem/response/__init__.py
@@ -229,7 +229,7 @@ class ControlMessage(object):
     :returns: **list** of (str, str, str) tuples for the components of this message
     """
 
-    if stem.prereq.is_python_3() and not get_bytes:
+    if not get_bytes:
       return [(code, div, stem.util.str_tools._to_unicode(content)) for (code, div, content) in self._parsed_content]
     else:
       return list(self._parsed_content)
@@ -246,7 +246,7 @@ class ControlMessage(object):
     :returns: **str** of the socket data used to generate this message
     """
 
-    if stem.prereq.is_python_3() and not get_bytes:
+    if not get_bytes:
       return stem.util.str_tools._to_unicode(self._raw_content)
     else:
       return self._raw_content
@@ -286,8 +286,7 @@ class ControlMessage(object):
     """
 
     for _, _, content in self._parsed_content:
-      if stem.prereq.is_python_3():
-        content = stem.util.str_tools._to_unicode(content)
+      content = stem.util.str_tools._to_unicode(content)
 
       yield ControlLine(content)
 
@@ -304,9 +303,7 @@ class ControlMessage(object):
     """
 
     content = self._parsed_content[index][2]
-
-    if stem.prereq.is_python_3():
-      content = stem.util.str_tools._to_unicode(content)
+    content = stem.util.str_tools._to_unicode(content)
 
     return ControlLine(content)
 
@@ -534,7 +531,7 @@ def _parse_entry(line, quoted, escaped, get_bytes):
 
     next_entry = codecs.escape_decode(next_entry)[0]
 
-    if stem.prereq.is_python_3() and not get_bytes:
+    if not get_bytes:
       next_entry = stem.util.str_tools._to_unicode(next_entry)  # normalize back to str
 
   if get_bytes:
diff --git a/stem/response/events.py b/stem/response/events.py
index e634a5d6..9b6d8393 100644
--- a/stem/response/events.py
+++ b/stem/response/events.py
@@ -23,10 +23,6 @@ QUOTED_KW_ARG = re.compile('^(.*) ([A-Za-z0-9_]+)="(.*)"$')
 CELL_TYPE = re.compile('^[a-z0-9_]+$')
 PARSE_NEWCONSENSUS_EVENTS = True
 
-# TODO: We can remove the following when we drop python2.6 support.
-
-INT_TYPE = int if stem.prereq.is_python_3() else long
-
 
 class Event(stem.response.ControlMessage):
   """
@@ -163,7 +159,7 @@ class Event(stem.response.ControlMessage):
     attr_values = getattr(self, attr)
 
     if attr_values:
-      if stem.util._is_str(attr_values):
+      if isinstance(attr_values, (bytes, str)):
         attr_values = [attr_values]
 
       for value in attr_values:
@@ -284,8 +280,8 @@ class BandwidthEvent(Event):
     elif not self.read.isdigit() or not self.written.isdigit():
       raise stem.ProtocolError("A BW event's bytes sent and received should be a positive numeric value, received: %s" % self)
 
-    self.read = INT_TYPE(self.read)
-    self.written = INT_TYPE(self.written)
+    self.read = int(self.read)
+    self.written = int(self.written)
 
 
 class BuildTimeoutSetEvent(Event):
@@ -1095,8 +1091,8 @@ class StreamBwEvent(Event):
     elif not self.read.isdigit() or not self.written.isdigit():
       raise stem.ProtocolError("A STREAM_BW event's bytes sent and received should be a positive numeric value, received: %s" % self)
 
-    self.read = INT_TYPE(self.read)
-    self.written = INT_TYPE(self.written)
+    self.read = int(self.read)
+    self.written = int(self.written)
     self.time = self._iso_timestamp(self.time)
 
 
@@ -1174,8 +1170,8 @@ class ConnectionBandwidthEvent(Event):
     elif not tor_tools.is_valid_connection_id(self.id):
       raise stem.ProtocolError("Connection IDs must be one to sixteen alphanumeric characters, got '%s': %s" % (self.id, self))
 
-    self.read = INT_TYPE(self.read)
-    self.written = INT_TYPE(self.written)
+    self.read = int(self.read)
+    self.written = int(self.written)
 
     self._log_if_unrecognized('conn_type', stem.ConnectionType)
 
@@ -1247,7 +1243,7 @@ class CircuitBandwidthEvent(Event):
       value = getattr(self, attr)
 
       if value:
-        setattr(self, attr, INT_TYPE(value))
+        setattr(self, attr, int(value))
 
 
 class CellStatsEvent(Event):
diff --git a/stem/response/getinfo.py b/stem/response/getinfo.py
index 0b9766ba..27442ffd 100644
--- a/stem/response/getinfo.py
+++ b/stem/response/getinfo.py
@@ -53,8 +53,7 @@ class GetInfoResponse(stem.response.ControlMessage):
       except ValueError:
         raise stem.ProtocolError('GETINFO replies should only contain parameter=value mappings:\n%s' % self)
 
-      if stem.prereq.is_python_3():
-        key = stem.util.str_tools._to_unicode(key)
+      key = stem.util.str_tools._to_unicode(key)
 
       # if the value is a multiline value then it *must* be of the form
       # '<key>=\n<value>'
diff --git a/stem/response/protocolinfo.py b/stem/response/protocolinfo.py
index 1763e59f..46f6ab4f 100644
--- a/stem/response/protocolinfo.py
+++ b/stem/response/protocolinfo.py
@@ -108,9 +108,7 @@ class ProtocolInfoResponse(stem.response.ControlMessage):
 
         if line.is_next_mapping('COOKIEFILE', True, True):
           self.cookie_path = line.pop_mapping(True, True, get_bytes = True)[1].decode(sys.getfilesystemencoding())
-
-          if stem.prereq.is_python_3():
-            self.cookie_path = stem.util.str_tools._to_unicode(self.cookie_path)  # normalize back to str
+          self.cookie_path = stem.util.str_tools._to_unicode(self.cookie_path)  # normalize back to str
       elif line_type == 'VERSION':
         # Line format:
         #   VersionLine = "250-VERSION" SP "Tor=" TorVersion OptArguments CRLF
diff --git a/stem/socket.py b/stem/socket.py
index 26e8f22e..4ab534b8 100644
--- a/stem/socket.py
+++ b/stem/socket.py
@@ -204,21 +204,10 @@ class BaseSocket(object):
         except socket.error:
           pass
 
-        # Suppressing unexpected exceptions from close. For instance, if the
-        # socket's file has already been closed then with python 2.7 that raises
-        # with...
-        # error: [Errno 32] Broken pipe
-
-        try:
-          self._socket.close()
-        except:
-          pass
+        self._socket.close()
 
       if self._socket_file:
-        try:
-          self._socket_file.close()
-        except:
-          pass
+        self._socket_file.close()
 
       self._socket = None
       self._socket_file = None
@@ -680,14 +669,12 @@ def recv_message(control_file, arrived_at = None):
 
       log.info(ERROR_MSG % ('SocketClosed', 'socket file has been closed'))
       raise stem.SocketClosed('socket file has been closed')
-    except (socket.error, ValueError) as exc:
-      # When disconnected we get...
-      #
-      # Python 2:
-      #   socket.error: [Errno 107] Transport endpoint is not connected
+    except (OSError, ValueError) as exc:
+      # when disconnected this errors with...
       #
-      # Python 3:
-      #   ValueError: I/O operation on closed file.
+      #   * ValueError: I/O operation on closed file
+      #   * OSError: [Errno 107] Transport endpoint is not connected
+      #   * OSError: [Errno 9] Bad file descriptor
 
       log.info(ERROR_MSG % ('SocketClosed', 'received exception "%s"' % exc))
       raise stem.SocketClosed(exc)
@@ -710,9 +697,8 @@ def recv_message(control_file, arrived_at = None):
 
     status_code, divider, content = line[:3], line[3:4], line[4:-2]  # strip CRLF off content
 
-    if stem.prereq.is_python_3():
-      status_code = stem.util.str_tools._to_unicode(status_code)
-      divider = stem.util.str_tools._to_unicode(divider)
+    status_code = stem.util.str_tools._to_unicode(status_code)
+    divider = stem.util.str_tools._to_unicode(divider)
 
     # Most controller responses are single lines, in which case we don't need
     # so much overhead.
diff --git a/stem/util/__init__.py b/stem/util/__init__.py
index 5be29777..2bcc8a07 100644
--- a/stem/util/__init__.py
+++ b/stem/util/__init__.py
@@ -49,19 +49,10 @@ def _hash_value(val):
   if not HASH_TYPES:
     my_hash = 0
   else:
-    # TODO: I hate doing this but until Python 2.x support is dropped we
-    # can't readily be strict about bytes vs unicode for attributes. This
-    # is because test assertions often use strings, and normalizing this
-    # would require wrapping most with to_unicode() calls.
-    #
-    # This hack will go away when we drop Python 2.x support.
+    # Hashing common builtins (ints, bools, etc) provide consistant values but
+    # many others vary their value on interpreter invokation.
 
-    if _is_str(val):
-      my_hash = hash('str')
-    else:
-      # Hashing common builtins (ints, bools, etc) provide consistant values but many others vary their value on interpreter invokation.
-
-      my_hash = hash(str(type(val)))
+    my_hash = hash(str(type(val)))
 
   if isinstance(val, (tuple, list)):
     for v in val:
@@ -75,40 +66,6 @@ def _hash_value(val):
   return my_hash
 
 
-def _is_str(val):
-  """
-  Check if a value is a string. This will be removed when we no longer provide
-  backward compatibility for the Python 2.x series.
-
-  :param object val: value to be checked
-
-  :returns: **True** if the value is some form of string (unicode or bytes),
-    and **False** otherwise
-  """
-
-  if stem.prereq.is_python_3():
-    return isinstance(val, (bytes, str))
-  else:
-    return isinstance(val, (bytes, unicode))
-
-
-def _is_int(val):
-  """
-  Check if a value is an integer. This will be removed when we no longer
-  provide backward compatibility for the Python 2.x series.
-
-  :param object val: value to be checked
-
-  :returns: **True** if the value is some form of integer (int or long),
-    and **False** otherwise
-  """
-
-  if stem.prereq.is_python_3():
-    return isinstance(val, int)
-  else:
-    return isinstance(val, (int, long))
-
-
 def datetime_to_unix(timestamp):
   """
   Converts a utc datetime object to a unix timestamp.
@@ -120,11 +77,7 @@ def datetime_to_unix(timestamp):
   :returns: **float** for the unix timestamp of the given datetime object
   """
 
-  if stem.prereq._is_python_26():
-    delta = (timestamp - datetime.datetime(1970, 1, 1))
-    return delta.days * 86400 + delta.seconds
-  else:
-    return (timestamp - datetime.datetime(1970, 1, 1)).total_seconds()
+  return (timestamp - datetime.datetime(1970, 1, 1)).total_seconds()
 
 
 def _pubkey_bytes(key):
@@ -132,7 +85,7 @@ def _pubkey_bytes(key):
   Normalizes X25509 and ED25519 keys into their public key bytes.
   """
 
-  if _is_str(key):
+  if isinstance(key, (bytes, str)):
     return key
 
   if not stem.prereq.is_crypto_available():
diff --git a/stem/util/conf.py b/stem/util/conf.py
index b4580ed9..1dbcc243 100644
--- a/stem/util/conf.py
+++ b/stem/util/conf.py
@@ -157,6 +157,7 @@ Here's an expanation of what happened...
     +- get_value - provides the value for a given key as a string
 """
 
+import collections
 import inspect
 import os
 import threading
@@ -165,12 +166,6 @@ import stem.prereq
 
 from stem.util import log
 
-try:
-  # added in python 2.7
-  from collections import OrderedDict
-except ImportError:
-  from stem.util.ordereddict import OrderedDict
-
 CONFS = {}  # mapping of identifier to singleton instances of configs
 
 
@@ -453,9 +448,9 @@ class Config(object):
   """
 
   def __init__(self):
-    self._path = None        # location we last loaded from or saved to
-    self._contents = OrderedDict()  # configuration key/value pairs
-    self._listeners = []     # functors to be notified of config changes
+    self._path = None  # location we last loaded from or saved to
+    self._contents = collections.OrderedDict()  # configuration key/value pairs
+    self._listeners = []  # functors to be notified of config changes
 
     # used for accessing _contents
     self._contents_lock = threading.RLock()
@@ -640,14 +635,12 @@ class Config(object):
     """
 
     with self._contents_lock:
-      unicode_type = str if stem.prereq.is_python_3() else unicode
-
       if value is None:
         if overwrite and key in self._contents:
           del self._contents[key]
         else:
           pass  # no value so this is a no-op
-      elif isinstance(value, (bytes, unicode_type)):
+      elif isinstance(value, (bytes, str)):
         if not overwrite and key in self._contents:
           self._contents[key].append(value)
         else:
@@ -735,7 +728,7 @@ class Config(object):
     elif isinstance(default, tuple):
       val = tuple(val)
     elif isinstance(default, dict):
-      val_map = OrderedDict()
+      val_map = collections.OrderedDict()
       for entry in val:
         if '=>' in entry:
           entry_key, entry_val = entry.split('=>', 1)
diff --git a/stem/util/connection.py b/stem/util/connection.py
index bd1fb5a2..f88b3f85 100644
--- a/stem/util/connection.py
+++ b/stem/util/connection.py
@@ -62,6 +62,7 @@ import re
 import socket
 import sys
 import time
+import urllib.request
 
 import stem
 import stem.util
@@ -70,12 +71,6 @@ import stem.util.system
 
 from stem.util import conf, enum, log, str_tools
 
-try:
-  # account for urllib's change between python 2.x and 3.x
-  import urllib.request as urllib
-except ImportError:
-  import urllib2 as urllib
-
 # Connection resolution is risky to log about since it's highly likely to
 # contain sensitive information. That said, it's also difficult to get right in
 # a platform independent fashion. To opt into the logging requried to
@@ -197,7 +192,7 @@ def download(url, timeout = None, retries = None):
   start_time = time.time()
 
   try:
-    return urllib.urlopen(url, timeout = timeout).read()
+    return urllib.request.urlopen(url, timeout = timeout).read()
   except socket.timeout as exc:
     raise stem.DownloadTimeout(url, exc, sys.exc_info()[2], timeout)
   except:
@@ -458,7 +453,7 @@ def is_valid_ipv4_address(address):
 
   if isinstance(address, bytes):
     address = str_tools._to_unicode(address)
-  elif not stem.util._is_str(address):
+  elif not isinstance(address, (bytes, str)):
     return False
 
   # checks if theres four period separated values
@@ -488,7 +483,7 @@ def is_valid_ipv6_address(address, allow_brackets = False):
 
   if isinstance(address, bytes):
     address = str_tools._to_unicode(address)
-  elif not stem.util._is_str(address):
+  elif not isinstance(address, (bytes, str)):
     return False
 
   if allow_brackets:
diff --git a/stem/util/enum.py b/stem/util/enum.py
index 76a52a55..abaf2490 100644
--- a/stem/util/enum.py
+++ b/stem/util/enum.py
@@ -76,7 +76,7 @@ class Enum(object):
     keys, values = [], []
 
     for entry in args:
-      if stem.util._is_str(entry):
+      if isinstance(entry, (bytes, str)):
         key, val = entry, _to_camel_case(entry)
       elif isinstance(entry, tuple) and len(entry) == 2:
         key, val = entry
diff --git a/stem/util/log.py b/stem/util/log.py
index e8d61c1d..4ef977b1 100644
--- a/stem/util/log.py
+++ b/stem/util/log.py
@@ -153,8 +153,7 @@ def escape(message):
   :returns: str that is escaped
   """
 
-  if stem.prereq.is_python_3():
-    message = stem.util.str_tools._to_unicode(message)
+  message = stem.util.str_tools._to_unicode(message)
 
   for pattern, replacement in (('\n', '\\n'), ('\r', '\\r'), ('\t', '\\t')):
     message = message.replace(pattern, replacement)
@@ -232,13 +231,7 @@ class LogBuffer(logging.Handler):
   """
 
   def __init__(self, runlevel, yield_records = False):
-    # TODO: At least in python 2.6 logging.Handler has a bug in that it doesn't
-    # extend object, causing our super() call to fail. When we drop python 2.6
-    # support we should switch back to using super() instead.
-    #
-    # super(LogBuffer, self).__init__(level = logging_level(runlevel))
-
-    logging.Handler.__init__(self, level = logging_level(runlevel))
+    super(LogBuffer, self).__init__(level = logging_level(runlevel))
 
     self.formatter = FORMATTER
     self._buffer = []
diff --git a/stem/util/lru_cache.py b/stem/util/lru_cache.py
deleted file mode 100644
index 011d4456..00000000
--- a/stem/util/lru_cache.py
+++ /dev/null
@@ -1,182 +0,0 @@
-# Drop in replace for python 3.2's collections.lru_cache, from...
-# http://code.activestate.com/recipes/578078-py26-and-py30-backport-of-python-33s-lru-cache/
-#
-# ... which is under the MIT license. Stem users should *not* rely upon this
-# module. It will be removed when we drop support for python 3.2 and below.
-
-"""
-Memoization decorator that caches a function's return value. If later called
-with the same arguments then the cached value is returned rather than
-reevaluated.
-
-This is a a python 2.x port of `functools.lru_cache
-<http://docs.python.org/3/library/functools.html#functools.lru_cache>`_. If
-using python 3.2 or later you should use that instead.
-"""
-
-from collections import namedtuple
-from functools import update_wrapper
-from threading import RLock
-
-_CacheInfo = namedtuple('CacheInfo', ['hits', 'misses', 'maxsize', 'currsize'])
-
-
-class _HashedSeq(list):
-    __slots__ = 'hashvalue'
-
-    def __init__(self, tup, hash=hash):
-        self[:] = tup
-        self.hashvalue = hash(tup)
-
-    def __hash__(self):
-        return self.hashvalue
-
-
-def _make_key(args, kwds, typed,
-              kwd_mark = (object(),),
-              fasttypes = set([int, str, frozenset, type(None)]),
-              sorted=sorted, tuple=tuple, type=type, len=len):
-    'Make a cache key from optionally typed positional and keyword arguments'
-    key = args
-    if kwds:
-        sorted_items = sorted(kwds.items())
-        key += kwd_mark
-        for item in sorted_items:
-            key += item
-    if typed:
-        key += tuple(type(v) for v in args)
-        if kwds:
-            key += tuple(type(v) for k, v in sorted_items)
-    elif len(key) == 1 and type(key[0]) in fasttypes:
-        return key[0]
-    return _HashedSeq(key)
-
-
-def lru_cache(maxsize=100, typed=False):
-    """Least-recently-used cache decorator.
-
-    If *maxsize* is set to None, the LRU features are disabled and the cache
-    can grow without bound.
-
-    If *typed* is True, arguments of different types will be cached separately.
-    For example, f(3.0) and f(3) will be treated as distinct calls with
-    distinct results.
-
-    Arguments to the cached function must be hashable.
-
-    View the cache statistics named tuple (hits, misses, maxsize, currsize) with
-    f.cache_info().  Clear the cache and statistics with f.cache_clear().
-    Access the underlying function with f.__wrapped__.
-
-    See:  http://en.wikipedia.org/wiki/Cache_algorithms#Least_Recently_Used
-
-    """
-
-    # Users should only access the lru_cache through its public API:
-    #       cache_info, cache_clear, and f.__wrapped__
-    # The internals of the lru_cache are encapsulated for thread safety and
-    # to allow the implementation to change (including a possible C version).
-
-    def decorating_function(user_function):
-
-        cache = dict()
-        stats = [0, 0]                  # make statistics updateable non-locally
-        HITS, MISSES = 0, 1             # names for the stats fields
-        make_key = _make_key
-        cache_get = cache.get           # bound method to lookup key or return None
-        _len = len                      # localize the global len() function
-        lock = RLock()                  # because linkedlist updates aren't threadsafe
-        root = []                       # root of the circular doubly linked list
-        root[:] = [root, root, None, None]      # initialize by pointing to self
-        nonlocal_root = [root]                  # make updateable non-locally
-        PREV, NEXT, KEY, RESULT = 0, 1, 2, 3    # names for the link fields
-
-        if maxsize == 0:
-
-            def wrapper(*args, **kwds):
-                # no caching, just do a statistics update after a successful call
-                result = user_function(*args, **kwds)
-                stats[MISSES] += 1
-                return result
-
-        elif maxsize is None:
-
-            def wrapper(*args, **kwds):
-                # simple caching without ordering or size limit
-                key = make_key(args, kwds, typed)
-                result = cache_get(key, root)   # root used here as a unique not-found sentinel
-                if result is not root:
-                    stats[HITS] += 1
-                    return result
-                result = user_function(*args, **kwds)
-                cache[key] = result
-                stats[MISSES] += 1
-                return result
-
-        else:
-
-            def wrapper(*args, **kwds):
-                # size limited caching that tracks accesses by recency
-                key = make_key(args, kwds, typed) if kwds or typed else args
-                with lock:
-                    link = cache_get(key)
-                    if link is not None:
-                        # record recent use of the key by moving it to the front of the list
-                        root, = nonlocal_root
-                        link_prev, link_next, key, result = link
-                        link_prev[NEXT] = link_next
-                        link_next[PREV] = link_prev
-                        last = root[PREV]
-                        last[NEXT] = root[PREV] = link
-                        link[PREV] = last
-                        link[NEXT] = root
-                        stats[HITS] += 1
-                        return result
-                result = user_function(*args, **kwds)
-                with lock:
-                    root, = nonlocal_root
-                    if key in cache:
-                        # getting here means that this same key was added to the
-                        # cache while the lock was released.  since the link
-                        # update is already done, we need only return the
-                        # computed result and update the count of misses.
-                        pass
-                    elif _len(cache) >= maxsize:
-                        # use the old root to store the new key and result
-                        oldroot = root
-                        oldroot[KEY] = key
-                        oldroot[RESULT] = result
-                        # empty the oldest link and make it the new root
-                        root = nonlocal_root[0] = oldroot[NEXT]
-                        oldkey = root[KEY]
-                        root[KEY] = root[RESULT] = None
-                        # now update the cache dictionary for the new links
-                        del cache[oldkey]
-                        cache[key] = oldroot
-                    else:
-                        # put result in a new link at the front of the list
-                        last = root[PREV]
-                        link = [last, root, key, result]
-                        last[NEXT] = root[PREV] = cache[key] = link
-                    stats[MISSES] += 1
-                return result
-
-        def cache_info():
-            """Report cache statistics"""
-            with lock:
-                return _CacheInfo(stats[HITS], stats[MISSES], maxsize, len(cache))
-
-        def cache_clear():
-            """Clear the cache and cache statistics"""
-            with lock:
-                cache.clear()
-                root = nonlocal_root[0]
-                root[:] = [root, root, None, None]
-                stats[:] = [0, 0]
-
-        wrapper.__wrapped__ = user_function
-        wrapper.cache_info = cache_info
-        wrapper.cache_clear = cache_clear
-        return update_wrapper(wrapper, user_function)
-
-    return decorating_function
diff --git a/stem/util/ordereddict.py b/stem/util/ordereddict.py
deleted file mode 100644
index ec228f31..00000000
--- a/stem/util/ordereddict.py
+++ /dev/null
@@ -1,133 +0,0 @@
-# Drop in replacement for python 2.7's OrderedDict, from...
-# https://pypi.org/project/ordereddict/
-#
-# Stem users should *not* rely upon this module. It will be removed when we
-# drop support for python 2.6 and below.
-
-# Copyright (c) 2009 Raymond Hettinger
-#
-# Permission is hereby granted, free of charge, to any person
-# obtaining a copy of this software and associated documentation files
-# (the "Software"), to deal in the Software without restriction,
-# including without limitation the rights to use, copy, modify, merge,
-# publish, distribute, sublicense, and/or sell copies of the Software,
-# and to permit persons to whom the Software is furnished to do so,
-# subject to the following conditions:
-#
-#     The above copyright notice and this permission notice shall be
-#     included in all copies or substantial portions of the Software.
-#
-#     THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
-#     EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
-#     OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
-#     NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
-#     HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
-#     WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
-#     FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
-#     OTHER DEALINGS IN THE SOFTWARE.
-
-from UserDict import DictMixin
-
-
-class OrderedDict(dict, DictMixin):
-  def __init__(self, *args, **kwds):
-    if len(args) > 1:
-      raise TypeError('expected at most 1 arguments, got %d' % len(args))
-    try:
-      self.__end
-    except AttributeError:
-      self.clear()
-    self.update(*args, **kwds)
-
-  def clear(self):
-    self.__end = end = []
-    end += [None, end, end]         # sentinel node for doubly linked list
-    self.__map = {}                 # key --> [key, prev, next]
-    dict.clear(self)
-
-  def __setitem__(self, key, value):
-    if key not in self:
-      end = self.__end
-      curr = end[1]
-      curr[2] = end[1] = self.__map[key] = [key, curr, end]
-    dict.__setitem__(self, key, value)
-
-  def __delitem__(self, key):
-    dict.__delitem__(self, key)
-    key, prev, next = self.__map.pop(key)
-    prev[2] = next
-    next[1] = prev
-
-  def __iter__(self):
-    end = self.__end
-    curr = end[2]
-    while curr is not end:
-      yield curr[0]
-      curr = curr[2]
-
-  def __reversed__(self):
-    end = self.__end
-    curr = end[1]
-    while curr is not end:
-      yield curr[0]
-      curr = curr[1]
-
-  def popitem(self, last=True):
-    if not self:
-      raise KeyError('dictionary is empty')
-    if last:
-      key = reversed(self).next()
-    else:
-      key = iter(self).next()
-    value = self.pop(key)
-    return key, value
-
-  def __reduce__(self):
-    items = [[k, self[k]] for k in self]
-    tmp = self.__map, self.__end
-    del self.__map, self.__end
-    inst_dict = vars(self).copy()
-    self.__map, self.__end = tmp
-    if inst_dict:
-      return (self.__class__, (items,), inst_dict)
-    return self.__class__, (items,)
-
-  def keys(self):
-    return list(self)
-
-  setdefault = DictMixin.setdefault
-  update = DictMixin.update
-  pop = DictMixin.pop
-  values = DictMixin.values
-  items = DictMixin.items
-  iterkeys = DictMixin.iterkeys
-  itervalues = DictMixin.itervalues
-  iteritems = DictMixin.iteritems
-
-  def __repr__(self):
-    if not self:
-      return '%s()' % (self.__class__.__name__,)
-    return '%s(%r)' % (self.__class__.__name__, self.items())
-
-  def copy(self):
-    return self.__class__(self)
-
-  @classmethod
-  def fromkeys(cls, iterable, value=None):
-    d = cls()
-    for key in iterable:
-      d[key] = value
-    return d
-
-  def __eq__(self, other):
-    if isinstance(other, OrderedDict):
-      if len(self) != len(other):
-        return False
-      for p, q in zip(self.items(), other.items()):
-        if p != q:
-          return False
-      return True
-    return dict.__eq__(self, other)
-
-  def __ne__(self, other):
-    return not self == other
diff --git a/stem/util/proc.py b/stem/util/proc.py
index f0e0104f..ecb7f3f7 100644
--- a/stem/util/proc.py
+++ b/stem/util/proc.py
@@ -48,6 +48,7 @@ future, use them at your own risk.**
 """
 
 import base64
+import functools
 import os
 import platform
 import socket
@@ -68,11 +69,6 @@ try:
 except ImportError:
   IS_PWD_AVAILABLE = False
 
-if stem.prereq._is_lru_cache_available():
-  from functools import lru_cache
-else:
-  from stem.util.lru_cache import lru_cache
-
 # os.sysconf is only defined on unix
 try:
   CLOCK_TICKS = os.sysconf(os.sysconf_names['SC_CLK_TCK'])
@@ -88,7 +84,7 @@ Stat = stem.util.enum.Enum(
 )
 
 
-@lru_cache()
+@functools.lru_cache()
 def is_available():
   """
   Checks if proc information is available on this platform.
@@ -109,7 +105,7 @@ def is_available():
     return True
 
 
-@lru_cache()
+@functools.lru_cache()
 def system_start_time():
   """
   Provides the unix time (seconds since epoch) when the system started.
@@ -132,7 +128,7 @@ def system_start_time():
     raise exc
 
 
-@lru_cache()
+@functools.lru_cache()
 def physical_memory():
   """
   Provides the total physical memory on the system in bytes.
diff --git a/stem/util/str_tools.py b/stem/util/str_tools.py
index 58effbee..6b852f3d 100644
--- a/stem/util/str_tools.py
+++ b/stem/util/str_tools.py
@@ -61,30 +61,17 @@ TIME_UNITS = (
 
 _timestamp_re = re.compile(r'(\d{4})-(\d{2})-(\d{2}) (\d{2}):(\d{2}):(\d{2})')
 
-if stem.prereq.is_python_3():
-  def _to_bytes_impl(msg):
-    if isinstance(msg, str):
-      return codecs.latin_1_encode(msg, 'replace')[0]
-    else:
-      return msg
-
-  def _to_unicode_impl(msg):
-    if msg is not None and not isinstance(msg, str):
-      return msg.decode('utf-8', 'replace')
-    else:
-      return msg
-else:
-  def _to_bytes_impl(msg):
-    if msg is not None and isinstance(msg, unicode):
-      return codecs.latin_1_encode(msg, 'replace')[0]
-    else:
-      return msg
+def _to_bytes_impl(msg):
+  if isinstance(msg, str):
+    return codecs.latin_1_encode(msg, 'replace')[0]
+  else:
+    return msg
 
-  def _to_unicode_impl(msg):
-    if msg is not None and not isinstance(msg, unicode):
-      return msg.decode('utf-8', 'replace')
-    else:
-      return msg
+def _to_unicode_impl(msg):
+  if msg is not None and not isinstance(msg, str):
+    return msg.decode('utf-8', 'replace')
+  else:
+    return msg
 
 
 def _to_bytes(msg):
@@ -137,7 +124,7 @@ def _to_int(msg):
   :returns: **int** representation of the string
   """
 
-  if stem.prereq.is_python_3() and isinstance(msg, bytes):
+  if isinstance(msg, bytes):
     # iterating over bytes in python3 provides ints rather than characters
     return sum([pow(256, (len(msg) - i - 1)) * c for (i, c) in enumerate(msg)])
   else:
@@ -508,7 +495,7 @@ def _parse_timestamp(entry):
   :raises: **ValueError** if the timestamp is malformed
   """
 
-  if not stem.util._is_str(entry):
+  if not isinstance(entry, (bytes, str)):
     raise ValueError('parse_timestamp() input must be a str, got a %s' % type(entry))
 
   try:
@@ -534,7 +521,7 @@ def _parse_iso_timestamp(entry):
   :raises: **ValueError** if the timestamp is malformed
   """
 
-  if not stem.util._is_str(entry):
+  if not isinstance(entry, (bytes, str)):
     raise ValueError('parse_iso_timestamp() input must be a str, got a %s' % type(entry))
 
   # based after suggestions from...
diff --git a/stem/util/system.py b/stem/util/system.py
index 0d2262f5..e514c3a4 100644
--- a/stem/util/system.py
+++ b/stem/util/system.py
@@ -454,7 +454,7 @@ def is_running(command):
     if command_listing:
       command_listing = [c.strip() for c in command_listing]
 
-      if stem.util._is_str(command):
+      if isinstance(command, (bytes, str)):
         command = [command]
 
       for cmd in command:
diff --git a/stem/util/test_tools.py b/stem/util/test_tools.py
index c7dce7ce..d65b3ea4 100644
--- a/stem/util/test_tools.py
+++ b/stem/util/test_tools.py
@@ -56,15 +56,6 @@ ASYNC_TESTS = {}
 AsyncStatus = stem.util.enum.UppercaseEnum('PENDING', 'RUNNING', 'FINISHED')
 AsyncResult = collections.namedtuple('AsyncResult', 'type msg')
 
-# TODO: Providing a copy of SkipTest that works with python 2.6. This will be
-# dropped when we remove python 2.6 support.
-
-if stem.prereq._is_python_26():
-  class SkipTest(Exception):
-    'Notes that the test was skipped.'
-else:
-  SkipTest = unittest.case.SkipTest
-
 
 def assert_equal(expected, actual, msg = None):
   """
@@ -111,7 +102,7 @@ def skip(msg):
   :raises: **unittest.case.SkipTest** for this reason
   """
 
-  raise SkipTest(msg)
+  raise unittest.case.SkipTest(msg)
 
 
 def asynchronous(func):
@@ -159,9 +150,6 @@ class AsyncTest(object):
     self._status = AsyncStatus.PENDING
 
   def run(self, *runner_args, **kwargs):
-    if stem.prereq._is_python_26():
-      return  # not supported under python 2.6
-
     def _wrapper(conn, runner, args):
       os.nice(12)
 
@@ -170,7 +158,7 @@ class AsyncTest(object):
         conn.send(AsyncResult('success', None))
       except AssertionError as exc:
         conn.send(AsyncResult('failure', str(exc)))
-      except SkipTest as exc:
+      except unittest.case.SkipTest as exc:
         conn.send(AsyncResult('skipped', str(exc)))
       except:
         conn.send(AsyncResult('error', traceback.format_exc()))
@@ -209,9 +197,6 @@ class AsyncTest(object):
     self.result(None)
 
   def result(self, test):
-    if stem.prereq._is_python_26():
-      return  # not supported under python 2.6
-
     with self._process_lock:
       if self._status == AsyncStatus.PENDING:
         self.run()
@@ -259,21 +244,6 @@ class TimedTestRunner(unittest.TextTestRunner):
           TEST_RUNTIMES[self.id()] = time.time() - start_time
           return result
 
-        # TODO: remove and drop unnecessary 'returns' when dropping python 2.6
-        # support
-
-        def skipTest(self, message):
-          if not stem.prereq._is_python_26():
-            return super(original_type, self).skipTest(message)
-
-        # TODO: remove when dropping python 2.6 support
-
-        def assertItemsEqual(self, expected, actual):
-          if stem.prereq._is_python_26():
-            self.assertEqual(set(expected), set(actual))
-          else:
-            return super(original_type, self).assertItemsEqual(expected, actual)
-
         def assertRaisesWith(self, exc_type, exc_msg, func, *args, **kwargs):
           """
           Asserts the given invokation raises the expected excepiton. This is
@@ -287,16 +257,6 @@ class TimedTestRunner(unittest.TextTestRunner):
 
           return self.assertRaisesRegexp(exc_type, '^%s$' % re.escape(exc_msg), func, *args, **kwargs)
 
-        def assertRaisesRegexp(self, exc_type, exc_msg, func, *args, **kwargs):
-          if stem.prereq._is_python_26():
-            try:
-              func(*args, **kwargs)
-              self.fail('Expected a %s to be raised but nothing was' % exc_type)
-            except exc_type as exc:
-              self.assertTrue(re.search(exc_msg, str(exc), re.MULTILINE))
-          else:
-            return super(original_type, self).assertRaisesRegexp(exc_type, exc_msg, func, *args, **kwargs)
-
         def id(self):
           return '%s.%s.%s' % (original_type.__module__, original_type.__name__, self._testMethodName)
 
@@ -511,21 +471,6 @@ def stylistic_issues(paths, check_newlines = False, check_exception_keyword = Fa
           if '"""' in content:
             is_block_comment = not is_block_comment
 
-          if check_exception_keyword and content.startswith('except') and content.endswith(', exc:'):
-            # Python 2.6 - 2.7 supports two forms for exceptions...
-            #
-            #   except ValueError, exc:
-            #   except ValueError as exc:
-            #
-            # The former is the old method and no longer supported in python 3
-            # going forward.
-
-            # TODO: This check only works if the exception variable is called
-            # 'exc'. We should generalize this via a regex so other names work
-            # too.
-
-            issues.setdefault(filename, []).append(Issue(index + 1, "except clause should use 'as', not comma", line))
-
           if prefer_single_quotes and not is_block_comment:
             if '"' in content and "'" not in content and '"""' not in content and not content.endswith('\\'):
               # Checking if the line already has any single quotes since that
diff --git a/stem/version.py b/stem/version.py
index 6bf0befe..71f16e2c 100644
--- a/stem/version.py
+++ b/stem/version.py
@@ -84,6 +84,7 @@ easily parsed and compared, for instance...
   ===================================== ===========
 """
 
+import functools
 import os
 import re
 
@@ -92,11 +93,6 @@ import stem.util
 import stem.util.enum
 import stem.util.system
 
-if stem.prereq._is_lru_cache_available():
-  from functools import lru_cache
-else:
-  from stem.util.lru_cache import lru_cache
-
 # cache for the get_system_tor_version function
 VERSION_CACHE = {}
 
@@ -150,7 +146,7 @@ def get_system_tor_version(tor_cmd = 'tor'):
   return VERSION_CACHE[tor_cmd]
 
 
-@lru_cache()
+@functools.lru_cache()
 def _get_version(version_str):
   return Version(version_str)
 
diff --git a/test/integ/connection/authentication.py b/test/integ/connection/authentication.py
index 1ab6aae0..cd562e7b 100644
--- a/test/integ/connection/authentication.py
+++ b/test/integ/connection/authentication.py
@@ -280,7 +280,6 @@ class TestAuthenticate(unittest.TestCase):
 
     if test.runner.Torrc.PASSWORD not in runner.get_options() or test.runner.Torrc.COOKIE in runner.get_options():
       self.skipTest('(requires only password auth)')
-      return
 
     for i in range(10):
       with runner.get_tor_controller(False) as controller:
diff --git a/test/integ/connection/connect.py b/test/integ/connection/connect.py
index f4df233f..84b4a8fc 100644
--- a/test/integ/connection/connect.py
+++ b/test/integ/connection/connect.py
@@ -2,27 +2,19 @@
 Integration tests for the connect_* convenience functions.
 """
 
+import io
 import unittest
 
 import stem.connection
 import test.require
 import test.runner
 
-try:
-  from StringIO import StringIO
-except ImportError:
-  from io import StringIO
-
-try:
-  # added in python 3.3
-  from unittest.mock import patch
-except ImportError:
-  from mock import patch
+from unittest.mock import patch
 
 
 class TestConnect(unittest.TestCase):
   @test.require.controller
-  @patch('sys.stdout', new_callable = StringIO)
+  @patch('sys.stdout', new_callable = io.StringIO)
   def test_connect(self, stdout_mock):
     """
     Basic sanity checks for the connect function.
@@ -41,7 +33,7 @@ class TestConnect(unittest.TestCase):
     self.assertEqual('', stdout_mock.getvalue())
 
   @test.require.controller
-  @patch('sys.stdout', new_callable = StringIO)
+  @patch('sys.stdout', new_callable = io.StringIO)
   def test_connect_port(self, stdout_mock):
     """
     Basic sanity checks for the connect_port function.
@@ -63,7 +55,7 @@ class TestConnect(unittest.TestCase):
       self.assertEqual(control_socket, None)
 
   @test.require.controller
-  @patch('sys.stdout', new_callable = StringIO)
+  @patch('sys.stdout', new_callable = io.StringIO)
   def test_connect_socket_file(self, stdout_mock):
     """
     Basic sanity checks for the connect_socket_file function.
@@ -85,7 +77,7 @@ class TestConnect(unittest.TestCase):
       self.assertEqual(control_socket, None)
 
   @test.require.controller
-  @patch('sys.stdout', new_callable = StringIO)
+  @patch('sys.stdout', new_callable = io.StringIO)
   def test_connect_to_socks_port(self, stdout_mock):
     """
     Common user gotcha is connecting to the SocksPort or ORPort rather than the
diff --git a/test/integ/control/base_controller.py b/test/integ/control/base_controller.py
index 294eaee3..323b57c7 100644
--- a/test/integ/control/base_controller.py
+++ b/test/integ/control/base_controller.py
@@ -47,7 +47,6 @@ class TestBaseController(unittest.TestCase):
 
     if stem.util.system.is_mac():
       self.skipTest('(ticket #6235)')
-      return
 
     with test.runner.get_runner().get_tor_socket() as control_socket:
       controller = stem.control.BaseController(control_socket)
@@ -97,7 +96,6 @@ class TestBaseController(unittest.TestCase):
 
     if stem.util.system.is_mac():
       self.skipTest('(ticket #6235)')
-      return
 
     with test.runner.get_runner().get_tor_socket() as control_socket:
       controller = stem.control.BaseController(control_socket)
diff --git a/test/integ/control/controller.py b/test/integ/control/controller.py
index a32f66f0..257d9fbc 100644
--- a/test/integ/control/controller.py
+++ b/test/integ/control/controller.py
@@ -754,71 +754,70 @@ class TestController(unittest.TestCase):
     """
 
     runner = test.runner.get_runner()
-    tmpdir = tempfile.mkdtemp()
 
-    with runner.get_tor_controller() as controller:
-      try:
-        # successfully set a single option
-        connlimit = int(controller.get_conf('ConnLimit'))
-        controller.set_conf('connlimit', str(connlimit - 1))
-        self.assertEqual(connlimit - 1, int(controller.get_conf('ConnLimit')))
-
-        # successfully set a single list option
-        exit_policy = ['accept *:7777', 'reject *:*']
-        controller.set_conf('ExitPolicy', exit_policy)
-        self.assertEqual(exit_policy, controller.get_conf('ExitPolicy', multiple = True))
+    with tempfile.TemporaryDirectory() as tmpdir:
 
-        # fail to set a single option
+      with runner.get_tor_controller() as controller:
         try:
-          controller.set_conf('invalidkeyboo', 'abcde')
-          self.fail()
-        except stem.InvalidArguments as exc:
-          self.assertEqual(['invalidkeyboo'], exc.arguments)
+          # successfully set a single option
+          connlimit = int(controller.get_conf('ConnLimit'))
+          controller.set_conf('connlimit', str(connlimit - 1))
+          self.assertEqual(connlimit - 1, int(controller.get_conf('ConnLimit')))
 
-        # resets configuration parameters
-        controller.reset_conf('ConnLimit', 'ExitPolicy')
-        self.assertEqual(connlimit, int(controller.get_conf('ConnLimit')))
-        self.assertEqual(None, controller.get_conf('ExitPolicy'))
+          # successfully set a single list option
+          exit_policy = ['accept *:7777', 'reject *:*']
+          controller.set_conf('ExitPolicy', exit_policy)
+          self.assertEqual(exit_policy, controller.get_conf('ExitPolicy', multiple = True))
 
-        # successfully sets multiple config options
-        controller.set_options({
-          'connlimit': str(connlimit - 2),
-          'contactinfo': 'stem@testing',
-        })
+          # fail to set a single option
+          try:
+            controller.set_conf('invalidkeyboo', 'abcde')
+            self.fail()
+          except stem.InvalidArguments as exc:
+            self.assertEqual(['invalidkeyboo'], exc.arguments)
 
-        self.assertEqual(connlimit - 2, int(controller.get_conf('ConnLimit')))
-        self.assertEqual('stem@testing', controller.get_conf('contactinfo'))
+          # resets configuration parameters
+          controller.reset_conf('ConnLimit', 'ExitPolicy')
+          self.assertEqual(connlimit, int(controller.get_conf('ConnLimit')))
+          self.assertEqual(None, controller.get_conf('ExitPolicy'))
 
-        # fail to set multiple config options
-        try:
+          # successfully sets multiple config options
           controller.set_options({
+            'connlimit': str(connlimit - 2),
             'contactinfo': 'stem@testing',
-            'bombay': 'vadapav',
           })
-          self.fail()
-        except stem.InvalidArguments as exc:
-          self.assertEqual(['bombay'], exc.arguments)
 
-        # context-sensitive keys (the only retched things for which order matters)
-        controller.set_options((
-          ('HiddenServiceDir', tmpdir),
-          ('HiddenServicePort', '17234 127.0.0.1:17235'),
-        ))
-
-        self.assertEqual(tmpdir, controller.get_conf('HiddenServiceDir'))
-        self.assertEqual('17234 127.0.0.1:17235', controller.get_conf('HiddenServicePort'))
-      finally:
-        # reverts configuration changes
+          self.assertEqual(connlimit - 2, int(controller.get_conf('ConnLimit')))
+          self.assertEqual('stem@testing', controller.get_conf('contactinfo'))
 
-        controller.set_options((
-          ('ExitPolicy', 'reject *:*'),
-          ('ConnLimit', None),
-          ('ContactInfo', None),
-          ('HiddenServiceDir', None),
-          ('HiddenServicePort', None),
-        ), reset = True)
+          # fail to set multiple config options
+          try:
+            controller.set_options({
+              'contactinfo': 'stem@testing',
+              'bombay': 'vadapav',
+            })
+            self.fail()
+          except stem.InvalidArguments as exc:
+            self.assertEqual(['bombay'], exc.arguments)
+
+          # context-sensitive keys (the only retched things for which order matters)
+          controller.set_options((
+            ('HiddenServiceDir', tmpdir),
+            ('HiddenServicePort', '17234 127.0.0.1:17235'),
+          ))
+
+          self.assertEqual(tmpdir, controller.get_conf('HiddenServiceDir'))
+          self.assertEqual('17234 127.0.0.1:17235', controller.get_conf('HiddenServicePort'))
+        finally:
+          # reverts configuration changes
 
-        shutil.rmtree(tmpdir)
+          controller.set_options((
+            ('ExitPolicy', 'reject *:*'),
+            ('ConnLimit', None),
+            ('ContactInfo', None),
+            ('HiddenServiceDir', None),
+            ('HiddenServicePort', None),
+          ), reset = True)
 
   @test.require.controller
   def test_set_conf_for_usebridges(self):
@@ -1296,7 +1295,6 @@ class TestController(unittest.TestCase):
 
     if not os.path.exists(runner.get_test_dir('cached-microdescs')):
       self.skipTest('(no cached microdescriptors)')
-      return
 
     with runner.get_tor_controller() as controller:
       count = 0
@@ -1318,7 +1316,6 @@ class TestController(unittest.TestCase):
 
     if test.tor_version() >= Requirement.MICRODESCRIPTOR_IS_DEFAULT:
       self.skipTest('(requires server descriptors)')
-      return
 
     with runner.get_tor_controller() as controller:
       # we should balk at invalid content
@@ -1349,7 +1346,6 @@ class TestController(unittest.TestCase):
 
     if test.tor_version() >= Requirement.MICRODESCRIPTOR_IS_DEFAULT:
       self.skipTest('(requires server descriptors)')
-      return
 
     with runner.get_tor_controller() as controller:
       count = 0
@@ -1534,6 +1530,5 @@ class TestController(unittest.TestCase):
       if TEST_ROUTER_STATUS_ENTRY is None:
         # this is only likely to occure if we can't get descriptors
         self.skipTest('(no named relays)')
-        return
 
     return TEST_ROUTER_STATUS_ENTRY
diff --git a/test/integ/descriptor/collector.py b/test/integ/descriptor/collector.py
index 3af25c29..53f45ae5 100644
--- a/test/integ/descriptor/collector.py
+++ b/test/integ/descriptor/collector.py
@@ -93,7 +93,6 @@ class TestCollector(unittest.TestCase):
   def _test_index(self, compression):
     if compression and not compression.available:
       self.skipTest('(%s unavailable)' % compression)
-      return
 
     collector = stem.descriptor.collector.CollecTor()
     index = collector.index(compression = compression)
diff --git a/test/integ/descriptor/extrainfo_descriptor.py b/test/integ/descriptor/extrainfo_descriptor.py
index c0a4d30c..4bfb8f3f 100644
--- a/test/integ/descriptor/extrainfo_descriptor.py
+++ b/test/integ/descriptor/extrainfo_descriptor.py
@@ -28,7 +28,7 @@ class TestExtraInfoDescriptor(unittest.TestCase):
     descriptor_path = os.path.join(test_dir, 'cached-extrainfo')
 
     if not os.path.exists(descriptor_path):
-      raise stem.util.test_tools.SkipTest('(no cached descriptors)')
+      raise unittest.case.SkipTest('(no cached descriptors)')
 
     with open(descriptor_path, 'rb') as descriptor_file:
       for desc in stem.descriptor.parse_file(descriptor_file, 'extra-info 1.0', validate = True):
diff --git a/test/integ/descriptor/microdescriptor.py b/test/integ/descriptor/microdescriptor.py
index 3f2b20cb..4e67e15b 100644
--- a/test/integ/descriptor/microdescriptor.py
+++ b/test/integ/descriptor/microdescriptor.py
@@ -28,7 +28,7 @@ class TestMicrodescriptor(unittest.TestCase):
     descriptor_path = os.path.join(test_dir, 'cached-microdescs')
 
     if not os.path.exists(descriptor_path):
-      raise stem.util.test_tools.SkipTest('(no cached descriptors)')
+      raise unittest.case.SkipTest('(no cached descriptors)')
 
     with open(descriptor_path, 'rb') as descriptor_file:
       for desc in stem.descriptor.parse_file(descriptor_file, 'microdescriptor 1.0', validate = True):
diff --git a/test/integ/descriptor/networkstatus.py b/test/integ/descriptor/networkstatus.py
index b9684e6f..efe646f9 100644
--- a/test/integ/descriptor/networkstatus.py
+++ b/test/integ/descriptor/networkstatus.py
@@ -43,12 +43,12 @@ class TestNetworkStatus(unittest.TestCase):
     consensus_path = os.path.join(test_dir, 'cached-consensus')
 
     if not os.path.exists(consensus_path):
-      raise stem.util.test_tools.SkipTest('(no cached-consensus)')
+      raise unittest.case.SkipTest('(no cached-consensus)')
     elif stem.util.system.is_windows():
       # Unable to check memory usage on windows, so can't prevent hanging the
       # system if things go bad.
 
-      raise stem.util.test_tools.SkipTest('(unavailable on windows)')
+      raise unittest.case.SkipTest('(unavailable on windows)')
 
     count, reported_flags = 0, []
 
@@ -79,9 +79,9 @@ class TestNetworkStatus(unittest.TestCase):
     consensus_path = os.path.join(test_dir, 'cached-microdesc-consensus')
 
     if not os.path.exists(consensus_path):
-      raise stem.util.test_tools.SkipTest('(no cached-microdesc-consensus)')
+      raise unittest.case.SkipTest('(no cached-microdesc-consensus)')
     elif stem.util.system.is_windows():
-      raise stem.util.test_tools.SkipTest('(unavailable on windows)')
+      raise unittest.case.SkipTest('(unavailable on windows)')
 
     count, reported_flags = 0, []
 
diff --git a/test/integ/descriptor/server_descriptor.py b/test/integ/descriptor/server_descriptor.py
index a62ee8f6..8aa4388c 100644
--- a/test/integ/descriptor/server_descriptor.py
+++ b/test/integ/descriptor/server_descriptor.py
@@ -28,7 +28,7 @@ class TestServerDescriptor(unittest.TestCase):
     descriptor_path = os.path.join(test_dir, 'cached-descriptors')
 
     if not os.path.exists(descriptor_path):
-      raise stem.util.test_tools.SkipTest('(no cached descriptors)')
+      raise unittest.case.SkipTest('(no cached descriptors)')
 
     with open(descriptor_path, 'rb') as descriptor_file:
       for desc in stem.descriptor.parse_file(descriptor_file, 'server-descriptor 1.0', validate = True):
diff --git a/test/integ/directory/fallback.py b/test/integ/directory/fallback.py
index e12b2659..83c87a8d 100644
--- a/test/integ/directory/fallback.py
+++ b/test/integ/directory/fallback.py
@@ -33,7 +33,6 @@ class TestFallback(unittest.TestCase):
     # added so many fallbacks now that this takes a looong time. :(
 
     self.skipTest('(skipped by default)')
-    return
 
     unsuccessful = {}
     downloader = stem.descriptor.remote.DescriptorDownloader()
diff --git a/test/integ/installation.py b/test/integ/installation.py
index 2ac655aa..2f41ef58 100644
--- a/test/integ/installation.py
+++ b/test/integ/installation.py
@@ -110,9 +110,9 @@ class TestInstallation(unittest.TestCase):
     git_dir = os.path.join(test.STEM_BASE, '.git')
 
     if not stem.util.system.is_available('git'):
-      raise stem.util.test_tools.SkipTest('(git unavailable)')
+      raise unittest.case.SkipTest('(git unavailable)')
     elif not os.path.exists(git_dir):
-      raise stem.util.test_tools.SkipTest('(not a git checkout)')
+      raise unittest.case.SkipTest('(not a git checkout)')
 
     if os.path.exists(DIST_PATH):
       raise AssertionError("%s already exists, maybe you manually ran 'python setup.py sdist'?" % DIST_PATH)
@@ -127,8 +127,8 @@ class TestInstallation(unittest.TestCase):
 
       # tarball has a prefix 'stem-[verion]' directory so stipping that out
 
-      dist_tar = tarfile.open(os.path.join(DIST_PATH, 'stem-dry-run-%s.tar.gz' % stem.__version__))
-      tar_contents = ['/'.join(info.name.split('/')[1:]) for info in dist_tar.getmembers() if info.isfile()]
+      with tarfile.open(os.path.join(DIST_PATH, 'stem-dry-run-%s.tar.gz' % stem.__version__)) as dist_tar:
+        tar_contents = ['/'.join(info.name.split('/')[1:]) for info in dist_tar.getmembers() if info.isfile()]
 
       issues = []
 
diff --git a/test/integ/interpreter.py b/test/integ/interpreter.py
index 65d03fd3..32c52c28 100644
--- a/test/integ/interpreter.py
+++ b/test/integ/interpreter.py
@@ -38,10 +38,8 @@ class TestInterpreter(unittest.TestCase):
 
     if test.runner.Torrc.PASSWORD in test.runner.get_runner().get_options():
       self.skipTest('password auth unsupported')
-      return
     elif not READLINE_AVAILABLE:
       self.skipTest('readline unavailable')
-      return
 
     expected = ['250-config-file=%s' % test.runner.get_runner().get_torrc_path(), '250 OK']
     self.assertEqual(expected, _run_prompt('--run', 'GETINFO config-file'))
@@ -50,10 +48,8 @@ class TestInterpreter(unittest.TestCase):
   def test_running_file(self):
     if test.runner.Torrc.PASSWORD in test.runner.get_runner().get_options():
       self.skipTest('password auth unsupported')
-      return
     elif not READLINE_AVAILABLE:
       self.skipTest('readline unavailable')
-      return
 
     expected = [
       '250-config-file=%s' % test.runner.get_runner().get_torrc_path(),
diff --git a/test/integ/manual.py b/test/integ/manual.py
index ae0b2b16..3e721ac6 100644
--- a/test/integ/manual.py
+++ b/test/integ/manual.py
@@ -59,9 +59,6 @@ EXPECTED_EXIT_POLICY_DESCRIPTION_END = 'it applies to both IPv4 and IPv6 address
 
 
 class TestManual(unittest.TestCase):
-  # TODO: remove when dropping support for python 2.6
-  skip_reason = 'setUpClass() unsupported in python 2.6'
-
   @classmethod
   def setUpClass(self):
     self.man_path = None
@@ -91,15 +88,14 @@ class TestManual(unittest.TestCase):
     if self.man_path and os.path.exists(self.man_path):
       os.remove(self.man_path)
 
+  # TODO: replace with a 'require' annotation
+
   def requires_downloaded_manual(self):
     if self.skip_reason:
       self.skipTest(self.skip_reason)
-      return True
     elif self.download_error:
       self.fail(self.download_error)
 
-    return False
-
   def test_escapes_non_ascii(self):
     """
     Check that our manual parser escapes all non-ascii characters. If this
@@ -108,8 +104,7 @@ class TestManual(unittest.TestCase):
     stem/manual.py's _get_categories().
     """
 
-    if self.requires_downloaded_manual():
-      return
+    self.requires_downloaded_manual()
 
     def check(content):
       try:
@@ -131,8 +126,7 @@ class TestManual(unittest.TestCase):
     it has indented lines within it. Ensure we parse this correctly.
     """
 
-    if self.requires_downloaded_manual():
-      return
+    self.requires_downloaded_manual()
 
     manual = stem.manual.Manual.from_man(self.man_path)
     self.assertTrue(manual.config_options['ExitPolicy'].description.startswith(EXPECTED_EXIT_POLICY_DESCRIPTION_START))
@@ -143,8 +137,7 @@ class TestManual(unittest.TestCase):
     Check if the cached manual information bundled with Stem is up to date or not.
     """
 
-    if self.requires_downloaded_manual():
-      return
+    self.requires_downloaded_manual()
 
     cached_manual = stem.manual.Manual.from_cache()
     latest_manual = stem.manual.Manual.from_man(self.man_path)
@@ -158,8 +151,7 @@ class TestManual(unittest.TestCase):
     then go ahead and simply update these assertions.
     """
 
-    if self.requires_downloaded_manual():
-      return
+    self.requires_downloaded_manual()
 
     def assert_equal(category, expected, actual):
       if expected != actual:
@@ -208,8 +200,7 @@ class TestManual(unittest.TestCase):
     class to match.
     """
 
-    if self.requires_downloaded_manual():
-      return
+    self.requires_downloaded_manual()
 
     categories = stem.manual._get_categories(self.man_content)
 
@@ -230,8 +221,7 @@ class TestManual(unittest.TestCase):
     Check that all the configuration options tor supports are in the man page.
     """
 
-    if self.requires_downloaded_manual():
-      return
+    self.requires_downloaded_manual()
 
     with test.runner.get_runner().get_tor_controller() as controller:
       config_options_in_tor = set([line.split()[0] for line in controller.get_info('config/names').splitlines() if line.split()[1] != 'Virtual'])
diff --git a/test/integ/process.py b/test/integ/process.py
index 26346ece..e40c501a 100644
--- a/test/integ/process.py
+++ b/test/integ/process.py
@@ -9,7 +9,6 @@ import hashlib
 import os
 import random
 import re
-import shutil
 import subprocess
 import tempfile
 import threading
@@ -28,13 +27,9 @@ import test
 import test.require
 
 from contextlib import contextmanager
-from stem.util.test_tools import asynchronous, assert_equal, assert_in, skip
+from unittest.mock import patch, Mock
 
-try:
-  # added in python 3.3
-  from unittest.mock import patch, Mock
-except ImportError:
-  from mock import patch, Mock
+from stem.util.test_tools import asynchronous, assert_equal, assert_in, skip
 
 BASIC_RELAY_TORRC = """\
 SocksPort 9089
@@ -57,18 +52,8 @@ def random_port():
 
 
 @contextmanager
-def tmp_directory():
-  tmp_dir = tempfile.mkdtemp()
-
-  try:
-    yield tmp_dir
-  finally:
-    shutil.rmtree(tmp_dir)
-
-
-@contextmanager
 def torrc():
-  with tmp_directory() as data_directory:
+  with tempfile.TemporaryDirectory() as data_directory:
     torrc_path = os.path.join(data_directory, 'torrc')
 
     with open(torrc_path, 'w') as torrc_file:
@@ -106,7 +91,7 @@ def run_tor(tor_cmd, *args, **kwargs):
     elif not exit_status and expect_failure:
       raise AssertionError("Didn't expect tor to be able to start when we run: %s\n%s" % (' '.join(args), stdout))
 
-    return stem.util.str_tools._to_unicode(stdout) if stem.prereq.is_python_3() else stdout
+    return stem.util.str_tools._to_unicode(stdout)
 
 
 class TestProcess(unittest.TestCase):
@@ -177,12 +162,8 @@ class TestProcess(unittest.TestCase):
     # I'm not gonna even pretend to understand the following. Ported directly
     # from tor's test_cmdline_args.py.
 
-    if stem.prereq.is_python_3():
-      output_hex = binascii.a2b_hex(stem.util.str_tools._to_bytes(output).strip()[3:])
-      salt, how, hashed = output_hex[:8], output_hex[8], output_hex[9:]
-    else:
-      output_hex = binascii.a2b_hex(output.strip()[3:])
-      salt, how, hashed = output_hex[:8], ord(output_hex[8]), output_hex[9:]
+    output_hex = binascii.a2b_hex(stem.util.str_tools._to_bytes(output).strip()[3:])
+    salt, how, hashed = output_hex[:8], output_hex[8], output_hex[9:]
 
     count = (16 + (how & 15)) << ((how >> 4) + 6)
     stuff = salt + b'my_password'
@@ -236,7 +217,7 @@ class TestProcess(unittest.TestCase):
     output = run_tor(tor_cmd, '--list-fingerprint', with_torrc = True, expect_failure = True)
     assert_in("Clients don't have long-term identity keys. Exiting.", output, 'Should fail to start due to lacking an ORPort')
 
-    with tmp_directory() as data_directory:
+    with tempfile.TemporaryDirectory() as data_directory:
       torrc_path = os.path.join(data_directory, 'torrc')
 
       with open(torrc_path, 'w') as torrc_file:
@@ -332,7 +313,7 @@ class TestProcess(unittest.TestCase):
     if test.tor_version() < stem.version.Requirement.TORRC_VIA_STDIN:
       skip('(requires %s)' % stem.version.Requirement.TORRC_VIA_STDIN)
 
-    with tmp_directory() as data_directory:
+    with tempfile.TemporaryDirectory() as data_directory:
       torrc = BASIC_RELAY_TORRC % data_directory
       output = run_tor(tor_cmd, '-f', '-', '--dump-config', 'short', stdin = torrc)
       assert_equal(sorted(torrc.splitlines()), sorted(output.splitlines()))
@@ -390,7 +371,7 @@ class TestProcess(unittest.TestCase):
     it isn't.
     """
 
-    with tmp_directory() as data_directory:
+    with tempfile.TemporaryDirectory() as data_directory:
       # Tries running tor in another thread with the given timeout argument. This
       # issues an invalid torrc so we terminate right away if we get to the point
       # of actually invoking tor.
@@ -443,7 +424,7 @@ class TestProcess(unittest.TestCase):
     Exercises launch_tor_with_config when we write a torrc to disk.
     """
 
-    with tmp_directory() as data_directory:
+    with tempfile.TemporaryDirectory() as data_directory:
       control_port = random_port()
       control_socket, tor_process = None, None
 
@@ -487,7 +468,7 @@ class TestProcess(unittest.TestCase):
     if test.tor_version() < stem.version.Requirement.TORRC_VIA_STDIN:
       skip('(requires %s)' % stem.version.Requirement.TORRC_VIA_STDIN)
 
-    with tmp_directory() as data_directory:
+    with tempfile.TemporaryDirectory() as data_directory:
       control_port = random_port()
       control_socket, tor_process = None, None
 
@@ -529,7 +510,7 @@ class TestProcess(unittest.TestCase):
     #   [warn] Failed to parse/validate config: Failed to bind one of the listener ports.
     #   [err] Reading config failed--see warnings above.
 
-    with tmp_directory() as data_directory:
+    with tempfile.TemporaryDirectory() as data_directory:
       both_ports = random_port()
 
       try:
@@ -551,7 +532,7 @@ class TestProcess(unittest.TestCase):
     Runs launch_tor where it times out before completing.
     """
 
-    with tmp_directory() as data_directory:
+    with tempfile.TemporaryDirectory() as data_directory:
       start_time = time.time()
 
       try:
@@ -583,7 +564,7 @@ class TestProcess(unittest.TestCase):
     elif test.tor_version() < stem.version.Requirement.TAKEOWNERSHIP:
       skip('(requires %s)' % stem.version.Requirement.TAKEOWNERSHIP)
 
-    with tmp_directory() as data_directory:
+    with tempfile.TemporaryDirectory() as data_directory:
       sleep_process = subprocess.Popen(['sleep', '60'])
 
       tor_process = stem.process.launch_tor_with_config(
@@ -627,7 +608,7 @@ class TestProcess(unittest.TestCase):
     if test.tor_version() < stem.version.Requirement.TAKEOWNERSHIP:
       skip('(requires %s)' % stem.version.Requirement.TAKEOWNERSHIP)
 
-    with tmp_directory() as data_directory:
+    with tempfile.TemporaryDirectory() as data_directory:
       control_port = random_port()
 
       tor_process = stem.process.launch_tor_with_config(
diff --git a/test/integ/response/protocolinfo.py b/test/integ/response/protocolinfo.py
index 5d8c74f6..917b87c3 100644
--- a/test/integ/response/protocolinfo.py
+++ b/test/integ/response/protocolinfo.py
@@ -14,11 +14,7 @@ import test.integ.util.system
 import test.require
 import test.runner
 
-try:
-  # added in python 3.3
-  from unittest.mock import Mock, patch
-except ImportError:
-  from mock import Mock, patch
+from unittest.mock import Mock, patch
 
 
 class TestProtocolInfo(unittest.TestCase):
diff --git a/test/integ/util/connection.py b/test/integ/util/connection.py
index ed55ad89..861b8ba9 100644
--- a/test/integ/util/connection.py
+++ b/test/integ/util/connection.py
@@ -4,6 +4,7 @@ that we're running.
 """
 
 import unittest
+import urllib.request
 
 import stem
 import stem.util.connection
@@ -13,12 +14,6 @@ import test.runner
 
 from stem.util.connection import Resolver
 
-try:
-  # account for urllib's change between python 2.x and 3.x
-  import urllib.request as urllib
-except ImportError:
-  import urllib2 as urllib
-
 
 class TestConnection(unittest.TestCase):
   @test.require.ptrace
@@ -27,10 +22,8 @@ class TestConnection(unittest.TestCase):
 
     if test.runner.Torrc.PORT not in runner.get_options():
       self.skipTest('(no control port)')
-      return
     elif resolver not in stem.util.connection.system_resolvers():
       self.skipTest('(resolver unavailable on this platform)')
-      return
 
     with runner.get_tor_socket():
       connections = stem.util.connection.get_connections(resolver, process_pid = runner.get_pid())
@@ -60,7 +53,7 @@ class TestConnection(unittest.TestCase):
       self.assertEqual('Failed to download from https://no.such.testing.url (URLError): Name or service not known', str(exc))
       self.assertEqual('https://no.such.testing.url', exc.url)
       self.assertEqual('Name or service not known', exc.error.reason.strerror)
-      self.assertEqual(urllib.URLError, type(exc.error))
+      self.assertEqual(urllib.request.URLError, type(exc.error))
 
   def test_connections_by_proc(self):
     self.check_resolver(Resolver.PROC)
diff --git a/test/integ/util/proc.py b/test/integ/util/proc.py
index da4d6efc..315082d5 100644
--- a/test/integ/util/proc.py
+++ b/test/integ/util/proc.py
@@ -76,7 +76,6 @@ class TestProc(unittest.TestCase):
       return
     elif not os.access('/proc/net/tcp', os.R_OK) or not os.access('/proc/net/udp', os.R_OK):
       self.skipTest('(proc lacks read permissions)')
-      return
 
     # making a controller connection so that we have something to query for
     with runner.get_tor_socket():
diff --git a/test/integ/util/system.py b/test/integ/util/system.py
index 89019685..2a7ac07a 100644
--- a/test/integ/util/system.py
+++ b/test/integ/util/system.py
@@ -14,13 +14,9 @@ import stem.util.system
 import test.require
 import test.runner
 
-from stem.util.system import State, DaemonTask
+from unittest.mock import Mock, patch
 
-try:
-  # added in python 3.3
-  from unittest.mock import Mock, patch
-except ImportError:
-  from mock import Mock, patch
+from stem.util.system import State, DaemonTask
 
 
 def filter_system_call(prefixes):
@@ -287,15 +283,12 @@ class TestSystem(unittest.TestCase):
 
     if stem.util.system.is_windows():
       self.skipTest('(unavailable on windows)')
-      return
     elif stem.util.system.is_mac() or stem.util.system.is_gentoo():
       self.skipTest('(resolvers unavailable)')
-      return
     elif not stem.util.system.is_available('netstat') or \
              stem.util.system.is_available('sockstat') or \
               stem.util.system.is_available('lsof'):
       self.skipTest('(connection resolvers unavailable)')
-      return
 
     runner = test.runner.get_runner()
     tor_pid, tor_port = runner.get_pid(), test.runner.CONTROL_PORT
@@ -313,7 +306,6 @@ class TestSystem(unittest.TestCase):
 
     if stem.util.system.is_gentoo():
       self.skipTest('(unavailable on gentoo)')
-      return
 
     netstat_prefix = stem.util.system.GET_PID_BY_PORT_NETSTAT
 
@@ -353,7 +345,6 @@ class TestSystem(unittest.TestCase):
 
     if stem.util.system.is_mac() or stem.util.system.is_gentoo():
       self.skipTest('(resolvers unavailable)')
-      return
 
     lsof_prefix = stem.util.system.GET_PID_BY_PORT_LSOF
 
@@ -370,13 +361,14 @@ class TestSystem(unittest.TestCase):
     Checks the stem.util.system.pid_by_open_file function.
     """
 
+    # check a directory that doesn't exist
+
+    self.assertEqual(None, stem.util.system.pid_by_open_file('/no/such/path'))
+
     # check a directory that exists, but isn't claimed by any application
-    tmpdir = tempfile.mkdtemp()
-    self.assertEqual(None, stem.util.system.pid_by_open_file(tmpdir))
 
-    # check a directory that doesn't exist
-    os.rmdir(tmpdir)
-    self.assertEqual(None, stem.util.system.pid_by_open_file(tmpdir))
+    with tempfile.TemporaryDirectory() as tmpdir:
+      self.assertEqual(None, stem.util.system.pid_by_open_file(tmpdir))
 
   @require_path
   def test_pids_by_user(self):
@@ -397,7 +389,6 @@ class TestSystem(unittest.TestCase):
 
     if stem.util.system.is_windows():
       self.skipTest('(unavailable on windows)')
-      return
 
     runner = test.runner.get_runner()
     runner_pid, tor_cwd = runner.get_pid(), runner.get_tor_cwd()
@@ -537,7 +528,6 @@ class TestSystem(unittest.TestCase):
 
     if getpass.getuser() == 'root':
       self.skipTest('(running as root)')
-      return
 
     self.assertEqual(os.getcwd(), stem.util.system.expand_path('.'))
     self.assertEqual(os.getcwd(), stem.util.system.expand_path('./'))
@@ -568,7 +558,6 @@ class TestSystem(unittest.TestCase):
 
     if stem.prereq.is_pypy():
       self.skipTest('(unimplemented for pypy)')
-      return
 
     initial_name = stem.util.system.get_process_name()
     self.assertTrue('run_tests.py' in initial_name)
diff --git a/test/network.py b/test/network.py
index 5072c5b6..5fea625e 100644
--- a/test/network.py
+++ b/test/network.py
@@ -127,9 +127,7 @@ class Socks(_socket_socket):
 
     :param int expected_size: number of bytes to return
 
-    :returns:
-      * **str** in Python 2 (bytes is str)
-      * **bytes** in Python 3
+    :returns: **bytes** for the requested content
 
     :raises:
       * :class:`socket.error` for socket errors
@@ -152,32 +150,21 @@ class Socks(_socket_socket):
 
     :param list integers: list of ints to convert
 
-    :returns:
-      * **str** in Python 2 (bytes is str)
-      * **bytes** in Python 3
+    :returns: **bytes** for the requested content
     """
 
-    if bytes is str:
-      bytes_ = ''.join([chr(x) for x in integers])  # Python 2
-    else:
-      bytes_ = bytes(integers)                      # Python 3
-    return bytes_
+    return bytes(integers)
 
   def _bytes_to_ints(self, bytes_):
     """
-    Returns a tuple of integers converted from a string (Python 2) or
-    bytes (Python 3).
+    Returns a tuple of integers converted from bytes.
 
-    :param str,bytes bytes_: byte string to convert
+    :param bytes bytes_: byte string to convert
 
     :returns: **list** of ints
     """
 
-    try:
-      integers = [ord(x) for x in bytes_]  # Python 2
-    except TypeError:
-      integers = [x for x in bytes_]       # Python 3
-    return tuple(integers)
+    return tuple([x for x in bytes_])
 
   def _pack_string(self, string_):
     """
@@ -185,16 +172,10 @@ class Socks(_socket_socket):
 
     :param str string_: string to convert
 
-    :returns:
-      * **str** in Python 2 (bytes is str)
-      * **bytes** in Python 3
+    :returns: **bytes** for the requested content
     """
 
-    try:
-      return struct.pack('>%ss' % len(string_), string_)
-    except struct.error:
-      # Python 3: encode str to bytes
-      return struct.pack('>%ss' % len(string_), string_.encode())
+    return struct.pack('>%ss' % len(string_), string_.encode())
 
   def connect(self, address):
     """
diff --git a/test/task.py b/test/task.py
index 1fbcf9a4..19026165 100644
--- a/test/task.py
+++ b/test/task.py
@@ -14,7 +14,6 @@
   |- PYTHON_VERSION - checks our python version
   |- PLATFORM_VERSION - checks our operating system version
   |- CRYPTO_VERSION - checks our version of cryptography
-  |- MOCK_VERSION - checks our version of mock
   |- PYFLAKES_VERSION - checks our version of pyflakes
   |- PYCODESTYLE_VERSION - checks our version of pycodestyle
   |- CLEAN_PYC - removes any *.pyc without a corresponding *.py
@@ -25,6 +24,7 @@
   +- PYCODESTYLE_TASK - style checks
 """
 
+import importlib
 import os
 import platform
 import re
@@ -46,14 +46,6 @@ from test.output import STATUS, ERROR, NO_NL, println
 
 TASK_DESCRIPTION_WIDTH = 40
 
-try:
-  # TODO: remove check when dropping python 2.6 support
-
-  import importlib
-  HAS_IMPORTLIB = True
-except ImportError:
-  HAS_IMPORTLIB = False
-
 CONFIG = stem.util.conf.config_dict('test', {
   'integ.test_directory': './test/data',
   'test.unit_tests': '',
@@ -163,9 +155,6 @@ def _import_tests():
   register if they're asynchronous.
   """
 
-  if not HAS_IMPORTLIB:
-    return
-
   for module in (CONFIG['test.unit_tests'].splitlines() + CONFIG['test.integ_tests'].splitlines()):
     try:
       importlib.import_module(module.rsplit('.', 1)[0])
@@ -273,7 +262,7 @@ class Task(object):
       self.is_successful = True
       output_msg = 'running' if self._is_background_task else 'done'
 
-      if self.result and self.print_result and stem.util._is_str(self.result):
+      if self.result and self.print_result and isinstance(self.result, (bytes, str)):
         output_msg = self.result
       elif self.print_runtime:
         output_msg += ' (%0.1fs)' % (time.time() - start_time)
@@ -305,7 +294,7 @@ class ModuleVersion(Task):
     def version_check():
       if prereq_check is None or prereq_check():
         for module in modules:
-          if HAS_IMPORTLIB and stem.util.test_tools._module_exists(module):
+          if stem.util.test_tools._module_exists(module):
             return importlib.import_module(module).__version__
 
       return 'missing'
@@ -333,7 +322,6 @@ TOR_VERSION = Task('tor version', _check_tor_version)
 PYTHON_VERSION = Task('python version', _check_python_version)
 PLATFORM_VERSION = Task('operating system', _check_platform_version)
 CRYPTO_VERSION = ModuleVersion('cryptography version', 'cryptography', stem.prereq.is_crypto_available)
-MOCK_VERSION = ModuleVersion('mock version', ['unittest.mock', 'mock'], stem.prereq.is_mock_available)
 PYFLAKES_VERSION = ModuleVersion('pyflakes version', 'pyflakes')
 PYCODESTYLE_VERSION = ModuleVersion('pycodestyle version', ['pycodestyle', 'pep8'])
 CLEAN_PYC = Task('checking for orphaned .pyc files', _clean_orphaned_pyc, (SRC_PATHS,), print_runtime = True)
diff --git a/test/unit/client/size.py b/test/unit/client/size.py
index dcd5fea3..d3bb4a4a 100644
--- a/test/unit/client/size.py
+++ b/test/unit/client/size.py
@@ -11,8 +11,6 @@ from stem.client.datatype import Size
 class TestSize(unittest.TestCase):
   def test_attributes(self):
     self.assertEqual('CHAR', Size.CHAR.name)
-    self.assertEqual('!B', Size.CHAR.format)
-
     self.assertEqual(1, Size.CHAR.size)
     self.assertEqual(2, Size.SHORT.size)
     self.assertEqual(4, Size.LONG.size)
@@ -27,8 +25,8 @@ class TestSize(unittest.TestCase):
     self.assertRaisesWith(ValueError, 'Size.pack encodes an integer, but was a str', Size.CHAR.pack, 'hi')
     self.assertRaisesWith(ValueError, 'Packed values must be positive (attempted to pack -1 as a CHAR)', Size.CHAR.pack, -1)
 
-    bad_size = Size('BAD_SIZE', 1, '!H')
-    self.assertRaisesRegexp(ValueError, re.escape("'\\x00\\x12' is the wrong size for a BAD_SIZE field"), bad_size.pack, 18)
+    too_small = Size('TOO_SMALL', 1)
+    self.assertRaises(OverflowError, too_small.pack, 1800)
 
   def test_unpack(self):
     self.assertEqual(18, Size.CHAR.unpack(b'\x12'))
diff --git a/test/unit/connection/authentication.py b/test/unit/connection/authentication.py
index 117b39d9..f6241e0e 100644
--- a/test/unit/connection/authentication.py
+++ b/test/unit/connection/authentication.py
@@ -14,15 +14,11 @@ import unittest
 import stem.connection
 import test
 
+from unittest.mock import Mock, patch
+
 from stem.response import ControlMessage
 from stem.util import log
 
-try:
-  # added in python 3.3
-  from unittest.mock import Mock, patch
-except ImportError:
-  from mock import Mock, patch
-
 
 class TestAuthenticate(unittest.TestCase):
   @patch('stem.connection.get_protocolinfo')
diff --git a/test/unit/connection/connect.py b/test/unit/connection/connect.py
index 37ded2f5..175a1ebd 100644
--- a/test/unit/connection/connect.py
+++ b/test/unit/connection/connect.py
@@ -2,25 +2,18 @@
 Unit tests for the stem.connection.connect function.
 """
 
+import io
 import unittest
 
-try:
-  from StringIO import StringIO
-except ImportError:
-  from io import StringIO
-
-try:
-  from mock import Mock, patch
-except ImportError:
-  from unittest.mock import Mock, patch
-
 import stem
 import stem.connection
 import stem.socket
 
+from unittest.mock import Mock, patch
+
 
 class TestConnect(unittest.TestCase):
-  @patch('sys.stdout', new_callable = StringIO)
+  @patch('sys.stdout', new_callable = io.StringIO)
   @patch('stem.util.system.is_running')
   @patch('os.path.exists', Mock(return_value = True))
   @patch('stem.socket.ControlSocketFile', Mock(side_effect = stem.SocketError('failed')))
@@ -33,7 +26,7 @@ class TestConnect(unittest.TestCase):
     is_running_mock.return_value = True
     self._assert_connect_fails_with({}, stdout_mock, "Unable to connect to tor. Maybe it's running without a ControlPort?")
 
-  @patch('sys.stdout', new_callable = StringIO)
+  @patch('sys.stdout', new_callable = io.StringIO)
   @patch('os.path.exists')
   @patch('stem.util.system.is_running', Mock(return_value = True))
   @patch('stem.socket.ControlSocketFile', Mock(side_effect = stem.SocketError('failed')))
@@ -121,7 +114,7 @@ class TestConnect(unittest.TestCase):
     authenticate_mock.assert_any_call(control_socket, None, None)
     authenticate_mock.assert_any_call(control_socket, 'my_password', None)
 
-  @patch('sys.stdout', new_callable = StringIO)
+  @patch('sys.stdout', new_callable = io.StringIO)
   @patch('stem.connection.authenticate')
   def test_auth_failure(self, authenticate_mock, stdout_mock):
     control_socket = stem.socket.ControlPort(connect = False)
diff --git a/test/unit/control/controller.py b/test/unit/control/controller.py
index 94c1b65f..9628c913 100644
--- a/test/unit/control/controller.py
+++ b/test/unit/control/controller.py
@@ -14,17 +14,13 @@ import stem.socket
 import stem.util.system
 import stem.version
 
+from unittest.mock import Mock, patch
+
 from stem import ControllerError, DescriptorUnavailable, InvalidArguments, InvalidRequest, ProtocolError, UnsatisfiableRequest
 from stem.control import MALFORMED_EVENTS, _parse_circ_path, Listener, Controller, EventType
 from stem.response import ControlMessage
 from stem.exit_policy import ExitPolicy
 
-try:
-  # added in python 3.3
-  from unittest.mock import Mock, patch
-except ImportError:
-  from mock import Mock, patch
-
 NS_DESC = 'r %s %s u5lTXJKGsLKufRLnSyVqT7TdGYw 2012-12-30 22:02:49 77.223.43.54 9001 0\ns Fast Named Running Stable Valid\nw Bandwidth=75'
 TEST_TIMESTAMP = 12345
 
diff --git a/test/unit/descriptor/bandwidth_file.py b/test/unit/descriptor/bandwidth_file.py
index 3040c38b..9bee5f95 100644
--- a/test/unit/descriptor/bandwidth_file.py
+++ b/test/unit/descriptor/bandwidth_file.py
@@ -2,26 +2,17 @@
 Unit tests for stem.descriptor.bandwidth_file.
 """
 
+import collections
 import datetime
 import unittest
 
 import stem.descriptor
 
+from unittest.mock import Mock, patch
+
 from stem.descriptor.bandwidth_file import BandwidthFile
 from test.unit.descriptor import get_resource
 
-try:
-  # added in python 2.7
-  from collections import OrderedDict
-except ImportError:
-  from stem.util.ordereddict import OrderedDict
-
-try:
-  # added in python 3.3
-  from unittest.mock import Mock, patch
-except ImportError:
-  from mock import Mock, patch
-
 EXPECTED_MEASUREMENT_1 = {
   'scanner': '/scanner.1/scan-data/bws-0.0:0.8-done-2019-01-13-22:55:22',
   'measured_at': '1547441722',
@@ -272,7 +263,7 @@ class TestBandwidthFile(unittest.TestCase):
     Exercise the example in our content method's pydoc.
     """
 
-    content = BandwidthFile.content(OrderedDict([
+    content = BandwidthFile.content(collections.OrderedDict([
       ('timestamp', '12345'),
       ('version', '1.2.0'),
       ('content', []),
@@ -286,7 +277,7 @@ class TestBandwidthFile(unittest.TestCase):
     Include an unrecognized header field.
     """
 
-    desc = BandwidthFile.create(OrderedDict([('version', '1.1.0'), ('new_header', 'neat stuff')]))
+    desc = BandwidthFile.create(collections.OrderedDict([('version', '1.1.0'), ('new_header', 'neat stuff')]))
     self.assertEqual(EXPECTED_NEW_HEADER_CONTENT, str(desc))
     self.assertEqual('1.1.0', desc.version)
     self.assertEqual({'version': '1.1.0', 'new_header': 'neat stuff'}, desc.header)
@@ -309,7 +300,7 @@ class TestBandwidthFile(unittest.TestCase):
 
     self.assertRaisesWith(ValueError, "The 'version' header must be in the second position", BandwidthFile.from_str, WRONG_VERSION_POSITION, validate = True)
 
-    content = BandwidthFile.content(OrderedDict([
+    content = BandwidthFile.content(collections.OrderedDict([
       ('timestamp', '1410723598'),
       ('file_created', '2019-01-14T05:35:06'),
       ('version', '1.1.0'),
diff --git a/test/unit/descriptor/collector.py b/test/unit/descriptor/collector.py
index b4ff7636..99e19d7c 100644
--- a/test/unit/descriptor/collector.py
+++ b/test/unit/descriptor/collector.py
@@ -8,20 +8,13 @@ import unittest
 
 import stem.prereq
 
+from unittest.mock import Mock, patch
+
 from stem.descriptor import Compression, DocumentHandler
 from stem.descriptor.collector import CollecTor, File
 from test.unit.descriptor import get_resource
 from test.unit.descriptor.data.collector.index import EXAMPLE_INDEX
 
-try:
-  # added in python 3.3
-  from unittest.mock import Mock, patch
-except ImportError:
-  from mock import Mock, patch
-
-URL_OPEN = 'urllib.request.urlopen' if stem.prereq.is_python_3() else 'urllib2.urlopen'
-
-
 with open(get_resource('collector/index.json'), 'rb') as index_file:
   EXAMPLE_INDEX_JSON = index_file.read()
 
@@ -60,7 +53,7 @@ class TestCollector(unittest.TestCase):
 
   # tests for the CollecTor class
 
-  @patch(URL_OPEN)
+  @patch('urllib.request.urlopen')
   def test_index_plaintext(self, urlopen_mock):
     urlopen_mock.return_value = io.BytesIO(EXAMPLE_INDEX_JSON)
 
@@ -68,11 +61,10 @@ class TestCollector(unittest.TestCase):
     self.assertEqual(EXAMPLE_INDEX, collector.index(Compression.PLAINTEXT))
     urlopen_mock.assert_called_with('https://collector.torproject.org/index/index.json', timeout = None)
 
-  @patch(URL_OPEN)
+  @patch('urllib.request.urlopen')
   def test_index_gzip(self, urlopen_mock):
     if not Compression.GZIP.available:
       self.skipTest('(gzip compression unavailable)')
-      return
 
     import zlib
     urlopen_mock.return_value = io.BytesIO(zlib.compress(EXAMPLE_INDEX_JSON))
@@ -81,11 +73,10 @@ class TestCollector(unittest.TestCase):
     self.assertEqual(EXAMPLE_INDEX, collector.index(Compression.GZIP))
     urlopen_mock.assert_called_with('https://collector.torproject.org/index/index.json.gz', timeout = None)
 
-  @patch(URL_OPEN)
+  @patch('urllib.request.urlopen')
   def test_index_bz2(self, urlopen_mock):
     if not Compression.BZ2.available:
       self.skipTest('(bz2 compression unavailable)')
-      return
 
     import bz2
     urlopen_mock.return_value = io.BytesIO(bz2.compress(EXAMPLE_INDEX_JSON))
@@ -94,11 +85,10 @@ class TestCollector(unittest.TestCase):
     self.assertEqual(EXAMPLE_INDEX, collector.index(Compression.BZ2))
     urlopen_mock.assert_called_with('https://collector.torproject.org/index/index.json.bz2', timeout = None)
 
-  @patch(URL_OPEN)
+  @patch('urllib.request.urlopen')
   def test_index_lzma(self, urlopen_mock):
     if not Compression.LZMA.available:
       self.skipTest('(lzma compression unavailable)')
-      return
 
     import lzma
     urlopen_mock.return_value = io.BytesIO(lzma.compress(EXAMPLE_INDEX_JSON))
@@ -107,7 +97,7 @@ class TestCollector(unittest.TestCase):
     self.assertEqual(EXAMPLE_INDEX, collector.index(Compression.LZMA))
     urlopen_mock.assert_called_with('https://collector.torproject.org/index/index.json.xz', timeout = None)
 
-  @patch(URL_OPEN)
+  @patch('urllib.request.urlopen')
   def test_index_retries(self, urlopen_mock):
     urlopen_mock.side_effect = IOError('boom')
 
@@ -121,21 +111,17 @@ class TestCollector(unittest.TestCase):
     self.assertRaisesRegexp(IOError, 'boom', collector.index)
     self.assertEqual(5, urlopen_mock.call_count)
 
-  @patch(URL_OPEN, Mock(return_value = io.BytesIO(b'not json')))
+  @patch('urllib.request.urlopen', Mock(return_value = io.BytesIO(b'not json')))
   def test_index_malformed_json(self):
     collector = CollecTor()
-
-    if stem.prereq.is_python_3():
-      self.assertRaisesRegexp(ValueError, 'Expecting value: line 1 column 1', collector.index, Compression.PLAINTEXT)
-    else:
-      self.assertRaisesRegexp(ValueError, 'No JSON object could be decoded', collector.index, Compression.PLAINTEXT)
+    self.assertRaisesRegexp(ValueError, 'Expecting value: line 1 column 1', collector.index, Compression.PLAINTEXT)
 
   def test_index_malformed_compression(self):
     for compression in (Compression.GZIP, Compression.BZ2, Compression.LZMA):
       if not compression.available:
         continue
 
-      with patch(URL_OPEN, Mock(return_value = io.BytesIO(b'not compressed'))):
+      with patch('urllib.request.urlopen', Mock(return_value = io.BytesIO(b'not compressed'))):
         collector = CollecTor()
         self.assertRaisesRegexp(IOError, 'Failed to decompress as %s' % compression, collector.index, compression)
 
diff --git a/test/unit/descriptor/compression.py b/test/unit/descriptor/compression.py
index 3945bc9c..a51bba62 100644
--- a/test/unit/descriptor/compression.py
+++ b/test/unit/descriptor/compression.py
@@ -32,7 +32,6 @@ class TestCompression(unittest.TestCase):
 
     if not compression.available:
       self.skipTest('(%s unavailable)' % compression)
-      return
 
     with open(get_resource(filename), 'rb') as compressed_file:
       content = compression.decompress(compressed_file.read())
diff --git a/test/unit/descriptor/export.py b/test/unit/descriptor/export.py
index a33c1d42..d27ed241 100644
--- a/test/unit/descriptor/export.py
+++ b/test/unit/descriptor/export.py
@@ -2,13 +2,9 @@
 Unit tests for stem.descriptor.export.
 """
 
+import io
 import unittest
 
-try:
-  from StringIO import StringIO
-except ImportError:
-  from io import StringIO
-
 import stem.prereq
 
 from stem.descriptor.server_descriptor import RelayDescriptor, BridgeDescriptor
@@ -21,10 +17,6 @@ class TestExport(unittest.TestCase):
     Exports a single minimal tor server descriptor.
     """
 
-    if stem.prereq._is_python_26():
-      self.skipTest('(header added in python 2.7)')
-      return
-
     desc = RelayDescriptor.create({
       'router': 'caerSidi 71.35.133.197 9001 0 0',
       'published': '2012-03-01 17:15:27',
@@ -63,7 +55,7 @@ class TestExport(unittest.TestCase):
     desc = RelayDescriptor.create()
     desc_csv = export_csv(desc)
 
-    csv_buffer = StringIO()
+    csv_buffer = io.StringIO()
     export_csv_file(csv_buffer, desc)
 
     self.assertEqual(desc_csv, csv_buffer.getvalue())
@@ -73,10 +65,6 @@ class TestExport(unittest.TestCase):
     Checks that the default attributes for our csv output doesn't include private fields.
     """
 
-    if stem.prereq._is_python_26():
-      self.skipTest('(header added in python 2.7)')
-      return
-
     desc = RelayDescriptor.create()
     desc_csv = export_csv(desc)
 
diff --git a/test/unit/descriptor/hidden_service_v3.py b/test/unit/descriptor/hidden_service_v3.py
index 33507314..4004a94d 100644
--- a/test/unit/descriptor/hidden_service_v3.py
+++ b/test/unit/descriptor/hidden_service_v3.py
@@ -3,6 +3,7 @@ Unit tests for stem.descriptor.hidden_service for version 3.
 """
 
 import base64
+import collections
 import functools
 import unittest
 
@@ -13,6 +14,8 @@ import stem.prereq
 
 import test.require
 
+from unittest.mock import patch, Mock
+
 from stem.descriptor.hidden_service import (
   IntroductionPointV3,
   HiddenServiceDescriptorV3,
@@ -27,18 +30,6 @@ from test.unit.descriptor import (
   base_expect_invalid_attr_for_text,
 )
 
-try:
-  # added in python 2.7
-  from collections import OrderedDict
-except ImportError:
-  from stem.util.ordereddict import OrderedDict
-
-try:
-  # added in python 3.3
-  from unittest.mock import patch, Mock
-except ImportError:
-  from mock import patch, Mock
-
 require_sha3 = test.require.needs(stem.prereq._is_sha3_available, 'requires sha3')
 require_x25519 = test.require.needs(lambda: stem.descriptor.hidden_service.X25519_AVAILABLE, 'requires openssl x5509')
 
@@ -328,7 +319,7 @@ class TestHiddenServiceDescriptorV3(unittest.TestCase):
 
     # include optional parameters
 
-    desc = InnerLayer.create(OrderedDict((
+    desc = InnerLayer.create(collections.OrderedDict((
       ('intro-auth-required', 'ed25519'),
       ('single-onion-service', ''),
     )))
diff --git a/test/unit/descriptor/networkstatus/document_v3.py b/test/unit/descriptor/networkstatus/document_v3.py
index ce7cfdb7..93f98d77 100644
--- a/test/unit/descriptor/networkstatus/document_v3.py
+++ b/test/unit/descriptor/networkstatus/document_v3.py
@@ -2,6 +2,7 @@
 Unit tests for the NetworkStatusDocumentV3 of stem.descriptor.networkstatus.
 """
 
+import collections
 import datetime
 import io
 import unittest
@@ -31,12 +32,6 @@ from stem.descriptor.router_status_entry import (
 
 from test.unit.descriptor import get_resource
 
-try:
-  # added in python 2.7
-  from collections import OrderedDict
-except ImportError:
-  from stem.util.ordereddict import OrderedDict
-
 BANDWIDTH_WEIGHT_ENTRIES = (
   'Wbd', 'Wbe', 'Wbg', 'Wbm',
   'Wdb',
@@ -869,7 +864,7 @@ DnN5aFtYKiTc19qIC7Nmo+afPdDEf0MlJvEOP5EWl3w=
     Parses the parameters attributes.
     """
 
-    document = NetworkStatusDocumentV3.create(OrderedDict([
+    document = NetworkStatusDocumentV3.create(collections.OrderedDict([
       ('vote-status', 'vote'),
       ('recommended-client-protocols', 'HSDir=1 HSIntro=3'),
       ('recommended-relay-protocols', 'Cons=1 Desc=1'),
@@ -1231,7 +1226,7 @@ DnN5aFtYKiTc19qIC7Nmo+afPdDEf0MlJvEOP5EWl3w=
     COMMITMENT_1 = '1 sha3-256 4CAEC248004A0DC6CE86EBD5F608C9B05500C70C AAAAAFd4/kAaklgYr4ijHZjXXy/B354jQfL31BFhhE46nuOHSPITyw== AAAAAFd4/kCpZeis3yJyr//rz8hXCeeAhHa4k3lAcAiMJd1vEMTPuw=='
     COMMITMENT_2 = '1 sha3-256 598536A9DD4E6C0F18B4AD4B88C7875A0A29BA31 AAAAAFd4/kC7S920awC5/HF5RfX4fKZtYqjm6qMh9G91AcjZm13DQQ=='
 
-    authority = DirectoryAuthority.create(OrderedDict([
+    authority = DirectoryAuthority.create(collections.OrderedDict([
       ('shared-rand-participate', ''),
       ('shared-rand-commit', '%s\nshared-rand-commit %s' % (COMMITMENT_1, COMMITMENT_2)),
       ('shared-rand-previous-value', '8 hAQLxyt0U3gu7QR2owixRCbIltcyPrz3B0YBfUshOkE='),
diff --git a/test/unit/descriptor/reader.py b/test/unit/descriptor/reader.py
index 76d1d8f3..f49183e5 100644
--- a/test/unit/descriptor/reader.py
+++ b/test/unit/descriptor/reader.py
@@ -19,11 +19,7 @@ import stem.util.system
 
 import test.unit.descriptor
 
-try:
-  # added in python 3.3
-  from unittest.mock import patch
-except ImportError:
-  from mock import patch
+from unittest.mock import patch
 
 BASIC_LISTING = """
 /tmp 123
@@ -44,23 +40,13 @@ def _get_raw_tar_descriptors():
     test_path = os.path.join(DESCRIPTOR_TEST_DATA, 'descriptor_archive.tar')
     raw_descriptors = []
 
-    # TODO: revert to using the 'with' keyword for this when dropping python
-    # 2.6 support
-
-    tar_file = None
-
-    try:
-      tar_file = tarfile.open(test_path)
-
+    with tarfile.open(test_path) as tar_file:
       for tar_entry in tar_file:
         if tar_entry.isfile():
           entry = tar_file.extractfile(tar_entry)
           entry.readline()  # strip header
           raw_descriptors.append(entry.read().decode('utf-8', 'replace'))
           entry.close()
-    finally:
-      if tar_file:
-        tar_file.close()
 
     TAR_DESCRIPTORS = raw_descriptors
 
@@ -192,7 +178,6 @@ class TestDescriptorReader(unittest.TestCase):
 
     if getpass.getuser() == 'root':
       self.skipTest('(running as root)')
-      return
 
     # Skip the test on windows, since you can only set the file's
     # read-only flag with os.chmod(). For more information see...
@@ -558,10 +543,8 @@ class TestDescriptorReader(unittest.TestCase):
 
     if getpass.getuser() == 'root':
       self.skipTest('(running as root)')
-      return
     elif stem.util.system.is_windows():
       self.skipTest('(chmod not functional)')
-      return
 
     test_path = os.path.join(self.temp_directory, 'secret_file')
 
diff --git a/test/unit/descriptor/remote.py b/test/unit/descriptor/remote.py
index ab0ad3d7..d9893535 100644
--- a/test/unit/descriptor/remote.py
+++ b/test/unit/descriptor/remote.py
@@ -2,6 +2,7 @@
 Unit tests for stem.descriptor.remote.
 """
 
+import http.client
 import io
 import socket
 import time
@@ -13,26 +14,11 @@ import stem.descriptor.remote
 import stem.prereq
 import stem.util.str_tools
 
+from unittest.mock import patch, Mock, MagicMock
+
 from stem.descriptor.remote import Compression
 from test.unit.descriptor import read_resource
 
-try:
-  from http.client import HTTPMessage  # python3
-except ImportError:
-  from httplib import HTTPMessage  # python2
-
-try:
-  # added in python 3.3
-  from unittest.mock import patch, Mock, MagicMock
-except ImportError:
-  from mock import patch, Mock, MagicMock
-
-# The urlopen() method is in a different location depending on if we're using
-# python 2.x or 3.x. The 2to3 converter accounts for this in imports, but not
-# mock annotations.
-
-URL_OPEN = 'urllib.request.urlopen' if stem.prereq.is_python_3() else 'urllib2.urlopen'
-
 TEST_RESOURCE = '/tor/server/fp/9695DFC35FFEB861329B9F1AB04C46397020CE31'
 
 # Output from requesting moria1's descriptor from itself...
@@ -104,16 +90,13 @@ def _dirport_mock(data, encoding = 'identity'):
   dirport_mock = Mock()
   dirport_mock().read.return_value = data
 
-  if stem.prereq.is_python_3():
-    headers = HTTPMessage()
+  headers = http.client.HTTPMessage()
 
-    for line in HEADER.splitlines():
-      key, value = line.split(': ', 1)
-      headers.add_header(key, encoding if key == 'Content-Encoding' else value)
+  for line in HEADER.splitlines():
+    key, value = line.split(': ', 1)
+    headers.add_header(key, encoding if key == 'Content-Encoding' else value)
 
-    dirport_mock().headers = headers
-  else:
-    dirport_mock().headers = HTTPMessage(io.BytesIO(HEADER % encoding))
+  dirport_mock().headers = headers
 
   return dirport_mock
 
@@ -165,7 +148,7 @@ class TestDescriptorDownloader(unittest.TestCase):
 
       self.assertRaisesRegexp(stem.ProtocolError, "^Response should begin with HTTP success, but was 'HTTP/1.0 500 Kaboom'", request.run)
 
-  @patch(URL_OPEN, _dirport_mock(TEST_DESCRIPTOR))
+  @patch('urllib.request.urlopen', _dirport_mock(TEST_DESCRIPTOR))
   def test_using_dirport(self):
     """
     Download a descriptor through the DirPort.
@@ -203,7 +186,7 @@ class TestDescriptorDownloader(unittest.TestCase):
       query = stem.descriptor.remote.Query(TEST_RESOURCE, compression = Compression.LZMA, start = False)
       self.assertEqual([stem.descriptor.Compression.PLAINTEXT], query.compression)
 
-  @patch(URL_OPEN, _dirport_mock(read_resource('compressed_identity'), encoding = 'identity'))
+  @patch('urllib.request.urlopen', _dirport_mock(read_resource('compressed_identity'), encoding = 'identity'))
   def test_compression_plaintext(self):
     """
     Download a plaintext descriptor.
@@ -218,7 +201,7 @@ class TestDescriptorDownloader(unittest.TestCase):
     self.assertEqual(1, len(descriptors))
     self.assertEqual('moria1', descriptors[0].nickname)
 
-  @patch(URL_OPEN, _dirport_mock(read_resource('compressed_gzip'), encoding = 'gzip'))
+  @patch('urllib.request.urlopen', _dirport_mock(read_resource('compressed_gzip'), encoding = 'gzip'))
   def test_compression_gzip(self):
     """
     Download a gip compressed descriptor.
@@ -233,7 +216,7 @@ class TestDescriptorDownloader(unittest.TestCase):
     self.assertEqual(1, len(descriptors))
     self.assertEqual('moria1', descriptors[0].nickname)
 
-  @patch(URL_OPEN, _dirport_mock(read_resource('compressed_zstd'), encoding = 'x-zstd'))
+  @patch('urllib.request.urlopen', _dirport_mock(read_resource('compressed_zstd'), encoding = 'x-zstd'))
   def test_compression_zstd(self):
     """
     Download a zstd compressed descriptor.
@@ -241,7 +224,6 @@ class TestDescriptorDownloader(unittest.TestCase):
 
     if not stem.prereq.is_zstd_available():
       self.skipTest('(requires zstd module)')
-      return
 
     descriptors = list(stem.descriptor.remote.get_server_descriptors(
       '9695DFC35FFEB861329B9F1AB04C46397020CE31',
@@ -252,7 +234,7 @@ class TestDescriptorDownloader(unittest.TestCase):
     self.assertEqual(1, len(descriptors))
     self.assertEqual('moria1', descriptors[0].nickname)
 
-  @patch(URL_OPEN, _dirport_mock(read_resource('compressed_lzma'), encoding = 'x-tor-lzma'))
+  @patch('urllib.request.urlopen', _dirport_mock(read_resource('compressed_lzma'), encoding = 'x-tor-lzma'))
   def test_compression_lzma(self):
     """
     Download a lzma compressed descriptor.
@@ -260,7 +242,6 @@ class TestDescriptorDownloader(unittest.TestCase):
 
     if not stem.prereq.is_lzma_available():
       self.skipTest('(requires lzma module)')
-      return
 
     descriptors = list(stem.descriptor.remote.get_server_descriptors(
       '9695DFC35FFEB861329B9F1AB04C46397020CE31',
@@ -271,7 +252,7 @@ class TestDescriptorDownloader(unittest.TestCase):
     self.assertEqual(1, len(descriptors))
     self.assertEqual('moria1', descriptors[0].nickname)
 
-  @patch(URL_OPEN)
+  @patch('urllib.request.urlopen')
   def test_each_getter(self, dirport_mock):
     """
     Surface level exercising of each getter method for downloading descriptors.
@@ -288,7 +269,7 @@ class TestDescriptorDownloader(unittest.TestCase):
     downloader.get_bandwidth_file()
     downloader.get_detached_signatures()
 
-  @patch(URL_OPEN, _dirport_mock(TEST_DESCRIPTOR))
+  @patch('urllib.request.urlopen', _dirport_mock(TEST_DESCRIPTOR))
   def test_reply_headers(self):
     query = stem.descriptor.remote.get_server_descriptors('9695DFC35FFEB861329B9F1AB04C46397020CE31', start = False)
     self.assertEqual(None, query.reply_headers)  # initially we don't have a reply
@@ -311,7 +292,7 @@ class TestDescriptorDownloader(unittest.TestCase):
     self.assertEqual(1, len(descriptors))
     self.assertEqual('moria1', descriptors[0].nickname)
 
-  @patch(URL_OPEN, _dirport_mock(TEST_DESCRIPTOR))
+  @patch('urllib.request.urlopen', _dirport_mock(TEST_DESCRIPTOR))
   def test_query_download(self):
     """
     Check Query functionality when we successfully download a descriptor.
@@ -336,7 +317,7 @@ class TestDescriptorDownloader(unittest.TestCase):
     self.assertEqual('9695DFC35FFEB861329B9F1AB04C46397020CE31', desc.fingerprint)
     self.assertEqual(TEST_DESCRIPTOR, desc.get_bytes())
 
-  @patch(URL_OPEN, _dirport_mock(b'some malformed stuff'))
+  @patch('urllib.request.urlopen', _dirport_mock(b'some malformed stuff'))
   def test_query_with_malformed_content(self):
     """
     Query with malformed descriptor content.
@@ -363,7 +344,7 @@ class TestDescriptorDownloader(unittest.TestCase):
 
     self.assertRaises(ValueError, query.run)
 
-  @patch(URL_OPEN)
+  @patch('urllib.request.urlopen')
   def test_query_with_timeout(self, dirport_mock):
     def urlopen_call(*args, **kwargs):
       time.sleep(0.06)
@@ -398,7 +379,7 @@ class TestDescriptorDownloader(unittest.TestCase):
       expected_error = 'Endpoints must be an stem.ORPort, stem.DirPort, or two value tuple. ' + error_suffix
       self.assertRaisesWith(ValueError, expected_error, stem.descriptor.remote.Query, TEST_RESOURCE, 'server-descriptor 1.0', endpoints = endpoints)
 
-  @patch(URL_OPEN, _dirport_mock(TEST_DESCRIPTOR))
+  @patch('urllib.request.urlopen', _dirport_mock(TEST_DESCRIPTOR))
   def test_can_iterate_multiple_times(self):
     query = stem.descriptor.remote.Query(
       TEST_RESOURCE,
diff --git a/test/unit/descriptor/router_status_entry.py b/test/unit/descriptor/router_status_entry.py
index c428d6b2..7ee942e0 100644
--- a/test/unit/descriptor/router_status_entry.py
+++ b/test/unit/descriptor/router_status_entry.py
@@ -2,6 +2,7 @@
 Unit tests for stem.descriptor.router_status_entry.
 """
 
+import collections
 import datetime
 import functools
 import unittest
@@ -27,12 +28,6 @@ from stem.descriptor.router_status_entry import (
   _base64_to_hex,
 )
 
-try:
-  # Added in 2.7
-  from collections import OrderedDict
-except ImportError:
-  from stem.util.ordereddict import OrderedDict
-
 ENTRY_WITHOUT_ED25519 = """\
 r seele AAoQ1DAR6kkoo19hBAX5K0QztNw m0ynPuwzSextzsiXYJYA0Hce+Cs 2015-08-23 00:26:35 73.15.150.172 9001 0
 s Running Stable Valid
@@ -258,7 +253,7 @@ class TestRouterStatusEntry(unittest.TestCase):
     Parse a router status entry with an IPv6 address.
     """
 
-    expected_protocols = OrderedDict((
+    expected_protocols = collections.OrderedDict((
       ('Cons', [1]),
       ('Desc', [1]),
       ('DirCache', [1]),
diff --git a/test/unit/descriptor/server_descriptor.py b/test/unit/descriptor/server_descriptor.py
index d87d51e9..aeb58df1 100644
--- a/test/unit/descriptor/server_descriptor.py
+++ b/test/unit/descriptor/server_descriptor.py
@@ -2,6 +2,7 @@
 Unit tests for stem.descriptor.server_descriptor.
 """
 
+import collections
 import datetime
 import functools
 import hashlib
@@ -20,6 +21,8 @@ import stem.version
 import stem.util.str_tools
 import test.require
 
+from unittest.mock import Mock, patch
+
 from stem.client.datatype import CertType
 from stem.descriptor import DigestHash, DigestEncoding
 from stem.descriptor.certificate import ExtensionType
@@ -31,18 +34,6 @@ from test.unit.descriptor import (
   base_expect_invalid_attr_for_text,
 )
 
-try:
-  # Added in 2.7
-  from collections import OrderedDict
-except ImportError:
-  from stem.util.ordereddict import OrderedDict
-
-try:
-  # added in python 3.3
-  from unittest.mock import Mock, patch
-except ImportError:
-  from mock import Mock, patch
-
 TARFILE_FINGERPRINTS = set([
   'B6D83EC2D9E18B0A7A33428F8CFA9C536769E209',
   'E0BD57A11F00041A9789577C53A1B784473669E4',
@@ -74,16 +65,12 @@ class TestServerDescriptor(unittest.TestCase):
     Fetch server descriptors via parse_file() for a tarfile object.
     """
 
-    # TODO: When dropping python 2.6 support we can go back to using the 'with'
-    # keyword here.
+    with tarfile.open(get_resource('descriptor_archive.tar')) as tar_file:
+      descriptors = list(stem.descriptor.parse_file(tar_file))
+      self.assertEqual(3, len(descriptors))
 
-    tar_file = tarfile.open(get_resource('descriptor_archive.tar'))
-    descriptors = list(stem.descriptor.parse_file(tar_file))
-    self.assertEqual(3, len(descriptors))
-
-    fingerprints = set([desc.fingerprint for desc in descriptors])
-    self.assertEqual(TARFILE_FINGERPRINTS, fingerprints)
-    tar_file.close()
+      fingerprints = set([desc.fingerprint for desc in descriptors])
+      self.assertEqual(TARFILE_FINGERPRINTS, fingerprints)
 
   def test_metrics_descriptor(self):
     """
@@ -288,7 +275,7 @@ Qlx9HNCqCY877ztFRC624ja2ql6A2hBcuoYMbkHjcQ4=
     exc_msg = 'Server descriptor lacks a fingerprint. This is an optional field, but required to make a router status entry.'
     self.assertRaisesWith(ValueError, exc_msg, desc_without_fingerprint.make_router_status_entry)
 
-    desc = RelayDescriptor.create(OrderedDict((
+    desc = RelayDescriptor.create(collections.OrderedDict((
       ('router', 'caerSidi 71.35.133.197 9001 0 0'),
       ('published', '2012-02-29 04:03:19'),
       ('fingerprint', '4F0C 867D F0EF 6816 0568 C826 838F 482C EA7C FE44'),
diff --git a/test/unit/directory/authority.py b/test/unit/directory/authority.py
index 1c2a86b4..1574bea3 100644
--- a/test/unit/directory/authority.py
+++ b/test/unit/directory/authority.py
@@ -9,13 +9,7 @@ import stem
 import stem.directory
 import stem.prereq
 
-try:
-  # added in python 3.3
-  from unittest.mock import patch, Mock
-except ImportError:
-  from mock import patch, Mock
-
-URL_OPEN = 'urllib.request.urlopen' if stem.prereq.is_python_3() else 'urllib2.urlopen'
+from unittest.mock import patch, Mock
 
 AUTHORITY_GITWEB_CONTENT = b"""\
 "moria1 orport=9101 "
@@ -53,7 +47,7 @@ class TestAuthority(unittest.TestCase):
     self.assertTrue(len(authorities) > 4)
     self.assertEqual('128.31.0.39', authorities['moria1'].address)
 
-  @patch(URL_OPEN, Mock(return_value = io.BytesIO(AUTHORITY_GITWEB_CONTENT)))
+  @patch('urllib.request.urlopen', Mock(return_value = io.BytesIO(AUTHORITY_GITWEB_CONTENT)))
   def test_from_remote(self):
     expected = {
       'moria1': stem.directory.Authority(
@@ -77,6 +71,6 @@ class TestAuthority(unittest.TestCase):
 
     self.assertEqual(expected, stem.directory.Authority.from_remote())
 
-  @patch(URL_OPEN, Mock(return_value = io.BytesIO(b'')))
+  @patch('urllib.request.urlopen', Mock(return_value = io.BytesIO(b'')))
   def test_from_remote_empty(self):
     self.assertRaisesRegexp(stem.DownloadFailed, 'no content', stem.directory.Authority.from_remote)
diff --git a/test/unit/directory/fallback.py b/test/unit/directory/fallback.py
index 06b4510d..a7c54efb 100644
--- a/test/unit/directory/fallback.py
+++ b/test/unit/directory/fallback.py
@@ -2,6 +2,7 @@
 Unit tests for stem.directory.Fallback.
 """
 
+import collections
 import io
 import re
 import tempfile
@@ -11,19 +12,7 @@ import stem
 import stem.directory
 import stem.util.conf
 
-try:
-  # added in python 2.7
-  from collections import OrderedDict
-except ImportError:
-  from stem.util.ordereddict import OrderedDict
-
-try:
-  # added in python 3.3
-  from unittest.mock import patch, Mock
-except ImportError:
-  from mock import patch, Mock
-
-URL_OPEN = 'urllib.request.urlopen' if stem.prereq.is_python_3() else 'urllib2.urlopen'
+from unittest.mock import patch, Mock
 
 FALLBACK_GITWEB_CONTENT = b"""\
 /* type=fallback */
@@ -58,7 +47,7 @@ URL: https:onionoo.torproject.orguptime?first_seen_days=30-&flag=V2Dir&type=rela
 /* ===== */
 """
 
-HEADER = OrderedDict((
+HEADER = collections.OrderedDict((
   ('type', 'fallback'),
   ('version', '2.0.0'),
   ('timestamp', '20170526090242'),
@@ -75,7 +64,7 @@ class TestFallback(unittest.TestCase):
       'nickname': 'rueckgrat',
       'has_extrainfo': True,
       'orport_v6': ('2a01:4f8:162:51e2::2', 9001),
-      'header': OrderedDict((
+      'header': collections.OrderedDict((
         ('type', 'fallback'),
         ('version', '2.0.0'),
         ('timestamp', '20170526090242'),
@@ -95,7 +84,7 @@ class TestFallback(unittest.TestCase):
     self.assertTrue(len(fallbacks) > 10)
     self.assertEqual('185.13.39.197', fallbacks['001524DD403D729F08F7E5D77813EF12756CFA8D'].address)
 
-  @patch(URL_OPEN, Mock(return_value = io.BytesIO(FALLBACK_GITWEB_CONTENT)))
+  @patch('urllib.request.urlopen', Mock(return_value = io.BytesIO(FALLBACK_GITWEB_CONTENT)))
   def test_from_remote(self):
     expected = {
       '0756B7CD4DFC8182BE23143FAC0642F515182CEB': stem.directory.Fallback(
@@ -122,15 +111,15 @@ class TestFallback(unittest.TestCase):
 
     self.assertEqual(expected, stem.directory.Fallback.from_remote())
 
-  @patch(URL_OPEN, Mock(return_value = io.BytesIO(b'')))
+  @patch('urllib.request.urlopen', Mock(return_value = io.BytesIO(b'')))
   def test_from_remote_empty(self):
     self.assertRaisesRegexp(stem.DownloadFailed, 'no content', stem.directory.Fallback.from_remote)
 
-  @patch(URL_OPEN, Mock(return_value = io.BytesIO(b'\n'.join(FALLBACK_GITWEB_CONTENT.splitlines()[1:]))))
+  @patch('urllib.request.urlopen', Mock(return_value = io.BytesIO(b'\n'.join(FALLBACK_GITWEB_CONTENT.splitlines()[1:]))))
   def test_from_remote_no_header(self):
     self.assertRaisesRegexp(IOError, 'does not have a type field indicating it is fallback directory metadata', stem.directory.Fallback.from_remote)
 
-  @patch(URL_OPEN, Mock(return_value = io.BytesIO(FALLBACK_GITWEB_CONTENT.replace(b'version=2.0.0', b'version'))))
+  @patch('urllib.request.urlopen', Mock(return_value = io.BytesIO(FALLBACK_GITWEB_CONTENT.replace(b'version=2.0.0', b'version'))))
   def test_from_remote_malformed_header(self):
     self.assertRaisesRegexp(IOError, 'Malformed fallback directory header line: /\\* version \\*/', stem.directory.Fallback.from_remote)
 
@@ -145,7 +134,7 @@ class TestFallback(unittest.TestCase):
     }
 
     for entry, expected in test_values.items():
-      with patch(URL_OPEN, Mock(return_value = io.BytesIO(entry))):
+      with patch('urllib.request.urlopen', Mock(return_value = io.BytesIO(entry))):
         self.assertRaisesRegexp(IOError, re.escape(expected), stem.directory.Fallback.from_remote)
 
   def test_persistence(self):
diff --git a/test/unit/doctest.py b/test/unit/doctest.py
index 28eef0cf..84712dc2 100644
--- a/test/unit/doctest.py
+++ b/test/unit/doctest.py
@@ -15,13 +15,9 @@ import stem.util.system
 import stem.version
 import test
 
-from stem.response import ControlMessage
+from unittest.mock import Mock, patch
 
-try:
-  # added in python 3.3
-  from unittest.mock import Mock, patch
-except ImportError:
-  from mock import Mock, patch
+from stem.response import ControlMessage
 
 EXPECTED_CIRCUIT_STATUS = """\
 20 EXTENDED $718BCEA286B531757ACAFF93AE04910EA73DE617=KsmoinOK,$649F2D0ACF418F7CFC6539AB2257EB2D5297BAFA=Eskimo BUILD_FLAGS=NEED_CAPACITY PURPOSE=GENERAL TIME_CREATED=2012-12-06T13:51:11.433755
diff --git a/test/unit/exit_policy/policy.py b/test/unit/exit_policy/policy.py
index f6cf9957..0cb755ae 100644
--- a/test/unit/exit_policy/policy.py
+++ b/test/unit/exit_policy/policy.py
@@ -5,11 +5,7 @@ Unit tests for the stem.exit_policy.ExitPolicy class.
 import pickle
 import unittest
 
-try:
-  # added in python 3.3
-  from unittest.mock import Mock, patch
-except ImportError:
-  from mock import Mock, patch
+from unittest.mock import Mock, patch
 
 from stem.exit_policy import (
   DEFAULT_POLICY_RULES,
diff --git a/test/unit/installation.py b/test/unit/installation.py
index fd8709ba..4b2a795c 100644
--- a/test/unit/installation.py
+++ b/test/unit/installation.py
@@ -7,9 +7,6 @@ import test
 
 
 class TestInstallation(unittest.TestCase):
-  # TODO: remove when dropping support for python 2.6
-  skip_reason = 'setUpClass() unsupported in python 2.6'
-
   @classmethod
   def setUpClass(self):
     setup_path = os.path.join(test.STEM_BASE, 'setup.py')
@@ -25,7 +22,6 @@ class TestInstallation(unittest.TestCase):
   def test_installs_all_modules(self):
     if self.skip_reason:
       self.skipTest(self.skip_reason)
-      return True
 
     # Modules cited my our setup.py looks like...
     #
@@ -49,7 +45,6 @@ class TestInstallation(unittest.TestCase):
   def test_installs_all_data_files(self):
     if self.skip_reason:
       self.skipTest(self.skip_reason)
-      return True
 
     # Checking that we have all non-source files. Data looks like...
     #
diff --git a/test/unit/interpreter/__init__.py b/test/unit/interpreter/__init__.py
index 7c107687..a48a19bc 100644
--- a/test/unit/interpreter/__init__.py
+++ b/test/unit/interpreter/__init__.py
@@ -9,11 +9,7 @@ __all__ = [
   'help',
 ]
 
-try:
-  # added in python 3.3
-  from unittest.mock import Mock
-except ImportError:
-  from mock import Mock
+from unittest.mock import Mock
 
 GETINFO_NAMES = """
 info/names -- List of GETINFO options, types, and documentation.
diff --git a/test/unit/interpreter/autocomplete.py b/test/unit/interpreter/autocomplete.py
index 40bcab48..8971ddc7 100644
--- a/test/unit/interpreter/autocomplete.py
+++ b/test/unit/interpreter/autocomplete.py
@@ -1,15 +1,10 @@
 import unittest
 
-from stem.interpreter.autocomplete import _get_commands, Autocompleter
+from unittest.mock import Mock
 
+from stem.interpreter.autocomplete import _get_commands, Autocompleter
 from test.unit.interpreter import CONTROLLER
 
-try:
-  # added in python 3.3
-  from unittest.mock import Mock
-except ImportError:
-  from mock import Mock
-
 
 class TestAutocompletion(unittest.TestCase):
   def test_autocomplete_results_from_config(self):
diff --git a/test/unit/interpreter/commands.py b/test/unit/interpreter/commands.py
index 59ceadfe..412178e6 100644
--- a/test/unit/interpreter/commands.py
+++ b/test/unit/interpreter/commands.py
@@ -5,16 +5,12 @@ import stem
 import stem.response
 import stem.version
 
+from unittest.mock import Mock, patch
+
 from stem.interpreter.commands import ControlInterpreter, _get_fingerprint
 from stem.response import ControlMessage
 from test.unit.interpreter import CONTROLLER
 
-try:
-  # added in python 3.3
-  from unittest.mock import Mock, patch
-except ImportError:
-  from mock import Mock, patch
-
 EXPECTED_EVENTS_RESPONSE = """\
 \x1b[34mBW 15 25\x1b[0m
 \x1b[34mBW 758 570\x1b[0m
diff --git a/test/unit/manual.py b/test/unit/manual.py
index 72f847e5..e1891ca4 100644
--- a/test/unit/manual.py
+++ b/test/unit/manual.py
@@ -2,36 +2,21 @@
 Unit testing for the stem.manual module.
 """
 
+import collections
 import io
 import os
 import sqlite3
 import tempfile
 import unittest
+import urllib.request
 
 import stem.prereq
 import stem.manual
 import stem.util.system
 import test.require
 
-try:
-  # account for urllib's change between python 2.x and 3.x
-  import urllib.request as urllib
-except ImportError:
-  import urllib2 as urllib
-
-try:
-  # added in python 3.3
-  from unittest.mock import Mock, patch
-except ImportError:
-  from mock import Mock, patch
-
-try:
-  # added in python 2.7
-  from collections import OrderedDict
-except ImportError:
-  from stem.util.ordereddict import OrderedDict
-
-URL_OPEN = 'urllib.request.urlopen' if stem.prereq.is_python_3() else 'urllib2.urlopen'
+from unittest.mock import Mock, patch
+
 EXAMPLE_MAN_PATH = os.path.join(os.path.dirname(__file__), 'tor_man_example')
 UNKNOWN_OPTIONS_MAN_PATH = os.path.join(os.path.dirname(__file__), 'tor_man_with_unknown')
 
@@ -59,7 +44,7 @@ EXPECTED_FILES = {
   '$HOME/.torrc': 'Fallback location for torrc, if @CONFDIR@/torrc is not found.',
 }
 
-EXPECTED_CONFIG_OPTIONS = OrderedDict()
+EXPECTED_CONFIG_OPTIONS = collections.OrderedDict()
 
 EXPECTED_CONFIG_OPTIONS['BandwidthRate'] = stem.manual.ConfigOption(
   name = 'BandwidthRate',
@@ -91,6 +76,10 @@ EXPECTED_CONFIG_OPTIONS['Bridge'] = stem.manual.ConfigOption(
 
 CACHED_MANUAL = None
 
+TEMP_DIR_MOCK = Mock()
+TEMP_DIR_MOCK.__enter__ = Mock(return_value = '/no/such/path')
+TEMP_DIR_MOCK.__exit__ = Mock(return_value = False)
+
 
 def _cached_manual():
   global CACHED_MANUAL
@@ -154,7 +143,6 @@ class TestManual(unittest.TestCase):
 
     if not stem.manual.HAS_ENCODING_ARG:
       self.skipTest('(man lacks --encoding arg on OSX, BSD, and Slackware #18660)')
-      return
 
     manual = stem.manual.Manual.from_man(EXAMPLE_MAN_PATH)
 
@@ -175,7 +163,6 @@ class TestManual(unittest.TestCase):
 
     if not stem.manual.HAS_ENCODING_ARG:
       self.skipTest('(man lacks --encoding arg on OSX and BSD and Slackware, #18660)')
-      return
 
     manual = stem.manual.Manual.from_man(UNKNOWN_OPTIONS_MAN_PATH)
 
@@ -203,7 +190,6 @@ class TestManual(unittest.TestCase):
 
     if not stem.manual.HAS_ENCODING_ARG:
       self.skipTest('(man lacks --encoding arg on OSX, BSD and Slackware, #18660)')
-      return
 
     manual = stem.manual.Manual.from_man(EXAMPLE_MAN_PATH)
 
@@ -220,7 +206,6 @@ class TestManual(unittest.TestCase):
 
     if not stem.manual.HAS_ENCODING_ARG:
       self.skipTest('(man lacks --encoding arg on OSX, BSD, and Slackware #18660)')
-      return
 
     manual = stem.manual.Manual.from_man(EXAMPLE_MAN_PATH)
 
@@ -249,40 +234,36 @@ class TestManual(unittest.TestCase):
     exc_msg = 'We require a2x from asciidoc to provide a man page'
     self.assertRaisesWith(IOError, exc_msg, stem.manual.download_man_page, '/tmp/no_such_file')
 
-  @patch('tempfile.mkdtemp', Mock(return_value = '/no/such/path'))
-  @patch('shutil.rmtree', Mock())
+  @patch('tempfile.TemporaryDirectory', Mock(return_value = TEMP_DIR_MOCK))
   @patch('stem.manual.open', Mock(side_effect = IOError('unable to write to file')), create = True)
   @patch('stem.util.system.is_available', Mock(return_value = True))
   def test_download_man_page_when_unable_to_write(self):
     exc_msg = "Unable to download tor's manual from https://gitweb.torproject.org/tor.git/plain/doc/tor.1.txt to /no/such/path/tor.1.txt: unable to write to file"
     self.assertRaisesWith(IOError, exc_msg, stem.manual.download_man_page, '/tmp/no_such_file')
 
-  @patch('tempfile.mkdtemp', Mock(return_value = '/no/such/path'))
-  @patch('shutil.rmtree', Mock())
+  @patch('tempfile.TemporaryDirectory', Mock(return_value = TEMP_DIR_MOCK))
   @patch('stem.manual.open', Mock(return_value = io.BytesIO()), create = True)
   @patch('stem.util.system.is_available', Mock(return_value = True))
-  @patch(URL_OPEN, Mock(side_effect = urllib.URLError('<urlopen error [Errno -2] Name or service not known>')))
+  @patch('urllib.request.urlopen', Mock(side_effect = urllib.request.URLError('<urlopen error [Errno -2] Name or service not known>')))
   def test_download_man_page_when_download_fails(self):
     exc_msg = "Unable to download tor's manual from https://www.atagar.com/foo/bar to /no/such/path/tor.1.txt: <urlopen error <urlopen error [Errno -2] Name or service not known>>"
     self.assertRaisesWith(IOError, exc_msg, stem.manual.download_man_page, '/tmp/no_such_file', url = 'https://www.atagar.com/foo/bar')
 
-  @patch('tempfile.mkdtemp', Mock(return_value = '/no/such/path'))
-  @patch('shutil.rmtree', Mock())
+  @patch('tempfile.TemporaryDirectory', Mock(return_value = TEMP_DIR_MOCK))
   @patch('stem.manual.open', Mock(return_value = io.BytesIO()), create = True)
   @patch('stem.util.system.call', Mock(side_effect = stem.util.system.CallError('call failed', 'a2x -f manpage /no/such/path/tor.1.txt', 1, None, None, 'call failed')))
   @patch('stem.util.system.is_available', Mock(return_value = True))
-  @patch(URL_OPEN, Mock(return_value = io.BytesIO(b'test content')))
+  @patch('urllib.request.urlopen', Mock(return_value = io.BytesIO(b'test content')))
   def test_download_man_page_when_a2x_fails(self):
     exc_msg = "Unable to run 'a2x -f manpage /no/such/path/tor.1.txt': call failed"
     self.assertRaisesWith(IOError, exc_msg, stem.manual.download_man_page, '/tmp/no_such_file', url = 'https://www.atagar.com/foo/bar')
 
-  @patch('tempfile.mkdtemp', Mock(return_value = '/no/such/path'))
-  @patch('shutil.rmtree', Mock())
+  @patch('tempfile.TemporaryDirectory', Mock(return_value = TEMP_DIR_MOCK))
   @patch('stem.manual.open', create = True)
   @patch('stem.util.system.call')
   @patch('stem.util.system.is_available', Mock(return_value = True))
   @patch('os.path.exists', Mock(return_value = True))
-  @patch(URL_OPEN, Mock(return_value = io.BytesIO(b'test content')))
+  @patch('urllib.request.urlopen', Mock(return_value = io.BytesIO(b'test content')))
   def test_download_man_page_when_successful(self, call_mock, open_mock):
     open_mock.side_effect = lambda path, *args: {
       '/no/such/path/tor.1.txt': io.BytesIO(),
@@ -315,4 +296,4 @@ class TestManual(unittest.TestCase):
     self.assertEqual({}, manual.commandline_options)
     self.assertEqual({}, manual.signals)
     self.assertEqual({}, manual.files)
-    self.assertEqual(OrderedDict(), manual.config_options)
+    self.assertEqual(collections.OrderedDict(), manual.config_options)
diff --git a/test/unit/response/events.py b/test/unit/response/events.py
index 82506e6d..27862054 100644
--- a/test/unit/response/events.py
+++ b/test/unit/response/events.py
@@ -10,16 +10,12 @@ import stem.response
 import stem.response.events
 import stem.util.log
 
+from unittest.mock import Mock
+
 from stem import *  # enums and exceptions
 from stem.response import ControlMessage
 from stem.descriptor.router_status_entry import RouterStatusEntryV3
 
-try:
-  # added in python 3.3
-  from unittest.mock import Mock
-except ImportError:
-  from mock import Mock
-
 # ADDRMAP event
 
 ADDRMAP = '650 ADDRMAP www.atagar.com 75.119.206.243 "2012-11-19 00:50:13" \
diff --git a/test/unit/response/protocolinfo.py b/test/unit/response/protocolinfo.py
index ab6dd0eb..dd8d2160 100644
--- a/test/unit/response/protocolinfo.py
+++ b/test/unit/response/protocolinfo.py
@@ -11,15 +11,11 @@ import stem.util.proc
 import stem.util.system
 import stem.version
 
+from unittest.mock import Mock, patch
+
 from stem.response import ControlMessage
 from stem.response.protocolinfo import AuthMethod
 
-try:
-  # added in python 3.3
-  from unittest.mock import Mock, patch
-except ImportError:
-  from mock import Mock, patch
-
 NO_AUTH = """250-PROTOCOLINFO 1
 250-AUTH METHODS=NULL
 250-VERSION Tor="0.2.1.30"
diff --git a/test/unit/tutorial.py b/test/unit/tutorial.py
index e866f3ca..91a70a32 100644
--- a/test/unit/tutorial.py
+++ b/test/unit/tutorial.py
@@ -7,6 +7,8 @@ import unittest
 
 import stem.descriptor.remote
 
+from unittest.mock import Mock, patch
+
 from stem.control import Controller
 from stem.descriptor.router_status_entry import RouterStatusEntryV2, RouterStatusEntryV3
 from stem.descriptor.networkstatus import NetworkStatusDocumentV3
@@ -14,17 +16,6 @@ from stem.descriptor.server_descriptor import RelayDescriptor
 from stem.exit_policy import ExitPolicy
 from test.unit import exec_documentation_example
 
-try:
-  from StringIO import StringIO
-except ImportError:
-  from io import StringIO
-
-try:
-  # added in python 3.3
-  from unittest.mock import Mock, patch
-except ImportError:
-  from mock import Mock, patch
-
 
 OVER_THE_RIVER_OUTPUT = """\
  * Connecting to tor
@@ -47,7 +38,7 @@ class TestTutorial(unittest.TestCase):
 
     stem.descriptor.remote.SINGLETON_DOWNLOADER = None
 
-  @patch('sys.stdout', new_callable = StringIO)
+  @patch('sys.stdout', new_callable = io.StringIO)
   @patch('stem.control.Controller.from_port', spec = Controller)
   def test_the_little_relay_that_could(self, from_port_mock, stdout_mock):
     controller = from_port_mock().__enter__()
@@ -59,7 +50,7 @@ class TestTutorial(unittest.TestCase):
     exec_documentation_example('hello_world.py')
     self.assertEqual('My Tor relay has read 33406 bytes and written 29649.\n', stdout_mock.getvalue())
 
-  @patch('sys.stdout', new_callable = StringIO)
+  @patch('sys.stdout', new_callable = io.StringIO)
   @patch('shutil.rmtree')
   @patch('stem.control.Controller.from_port', spec = Controller)
   def test_over_the_river(self, from_port_mock, rmtree_mock, stdout_mock):
@@ -125,7 +116,7 @@ class TestTutorial(unittest.TestCase):
 
     self.assertEqual(OVER_THE_RIVER_OUTPUT, stdout_mock.getvalue())
 
-  @patch('sys.stdout', new_callable = StringIO)
+  @patch('sys.stdout', new_callable = io.StringIO)
   @patch('stem.descriptor.remote.DescriptorDownloader')
   def test_mirror_mirror_on_the_wall_1(self, downloader_mock, stdout_mock):
     downloader_mock().get_consensus.return_value = [RouterStatusEntryV2.create({
@@ -135,7 +126,7 @@ class TestTutorial(unittest.TestCase):
     exec_documentation_example('current_descriptors.py')
     self.assertEqual('found relay caerSidi (A7569A83B5706AB1B1A9CB52EFF7D2D32E4553EB)\n', stdout_mock.getvalue())
 
-  @patch('sys.stdout', new_callable = StringIO)
+  @patch('sys.stdout', new_callable = io.StringIO)
   @patch('stem.control.Controller.from_port', spec = Controller)
   def test_mirror_mirror_on_the_wall_2(self, from_port_mock, stdout_mock):
     controller = from_port_mock().__enter__()
@@ -146,7 +137,7 @@ class TestTutorial(unittest.TestCase):
     exec_documentation_example('descriptor_from_tor_control_socket.py')
     self.assertEqual('found relay caerSidi (A7569A83B5706AB1B1A9CB52EFF7D2D32E4553EB)\n', stdout_mock.getvalue())
 
-  @patch('sys.stdout', new_callable = StringIO)
+  @patch('sys.stdout', new_callable = io.StringIO)
   @patch('%s.open' % __name__, create = True)
   def test_mirror_mirror_on_the_wall_3(self, open_mock, stdout_mock):
     def tutorial_example():
@@ -164,7 +155,7 @@ class TestTutorial(unittest.TestCase):
     tutorial_example()
     self.assertEqual('found relay caerSidi (A7569A83B5706AB1B1A9CB52EFF7D2D32E4553EB)\n', stdout_mock.getvalue())
 
-  @patch('sys.stdout', new_callable = StringIO)
+  @patch('sys.stdout', new_callable = io.StringIO)
   @patch('stem.descriptor.collector.get_server_descriptors')
   def test_mirror_mirror_on_the_wall_4(self, get_desc_mock, stdout_mock):
     get_desc_mock.return_value = iter([RelayDescriptor.create({
@@ -175,7 +166,7 @@ class TestTutorial(unittest.TestCase):
     exec_documentation_example('collector_reading.py')
     self.assertEqual('1 relays published an exiting policy today...\n\n  caerSidi (2C3C46625698B6D67DF32BC1918AD3EE1F9906B1)\n', stdout_mock.getvalue())
 
-  @patch('sys.stdout', new_callable = StringIO)
+  @patch('sys.stdout', new_callable = io.StringIO)
   @patch('stem.descriptor.remote.DescriptorDownloader')
   @patch('stem.prereq.is_crypto_available', Mock(return_value = False))
   def test_mirror_mirror_on_the_wall_5(self, downloader_mock, stdout_mock):
diff --git a/test/unit/tutorial_examples.py b/test/unit/tutorial_examples.py
index c4b26ad0..d96ff71b 100644
--- a/test/unit/tutorial_examples.py
+++ b/test/unit/tutorial_examples.py
@@ -2,19 +2,17 @@
 Tests for the examples given in stem's tutorial.
 """
 
+import io
 import itertools
 import os
 import unittest
 
-try:
-  from StringIO import StringIO
-except ImportError:
-  from io import StringIO
-
 import stem.response
 import stem.descriptor.remote
 import stem.prereq
 
+from unittest.mock import Mock, patch
+
 from stem.control import Controller
 from stem.descriptor.networkstatus import NetworkStatusDocumentV3
 from stem.descriptor.router_status_entry import RouterStatusEntryV3
@@ -24,12 +22,6 @@ from stem.response import ControlMessage
 
 from test.unit import exec_documentation_example
 
-try:
-  # added in python 3.3
-  from unittest.mock import Mock, patch
-except ImportError:
-  from mock import Mock, patch
-
 OPEN_FUNCTION = open  # make a reference so mocking open() won't mess with us
 
 CIRC_CONTENT = '650 CIRC %d %s \
@@ -129,13 +121,7 @@ def _get_router_status(address = None, port = None, nickname = None, fingerprint
 
 
 class TestTutorialExamples(unittest.TestCase):
-  def assert_equal_unordered(self, expected, actual):
-    if stem.prereq.is_python_3():
-      self.assertCountEqual(expected.splitlines(), actual.splitlines())
-    else:
-      self.assertItemsEqual(expected.splitlines(), actual.splitlines())
-
-  @patch('sys.stdout', new_callable = StringIO)
+  @patch('sys.stdout', new_callable = io.StringIO)
   @patch('stem.control.Controller.from_port', spec = Controller)
   def test_list_circuits(self, from_port_mock, stdout_mock):
     path_1 = ('B1FA7D51B8B6F0CB585D944F450E7C06EDE7E44C', 'ByTORAndTheSnowDog')
@@ -164,9 +150,9 @@ class TestTutorialExamples(unittest.TestCase):
     }[fingerprint]
 
     exec_documentation_example('list_circuits.py')
-    self.assert_equal_unordered(LIST_CIRCUITS_OUTPUT, stdout_mock.getvalue())
+    self.assertCountEqual(LIST_CIRCUITS_OUTPUT.splitlines(), stdout_mock.getvalue().splitlines())
 
-  @patch('sys.stdout', new_callable = StringIO)
+  @patch('sys.stdout', new_callable = io.StringIO)
   @patch('stem.control.Controller.from_port', spec = Controller)
   def test_exit_used(self, from_port_mock, stdout_mock):
     def tutorial_example(mock_event):
@@ -215,9 +201,9 @@ class TestTutorialExamples(unittest.TestCase):
     controller.get_info.return_value = 'unknown'
 
     tutorial_example(event)
-    self.assert_equal_unordered(EXIT_USED_OUTPUT, stdout_mock.getvalue())
+    self.assertCountEqual(EXIT_USED_OUTPUT.splitlines(), stdout_mock.getvalue().splitlines())
 
-  @patch('sys.stdout', new_callable = StringIO)
+  @patch('sys.stdout', new_callable = io.StringIO)
   @patch('stem.descriptor.remote.DescriptorDownloader')
   def test_outdated_relays(self, downloader_mock, stdout_mock):
     downloader_mock().get_server_descriptors.return_value = [
@@ -229,19 +215,12 @@ class TestTutorialExamples(unittest.TestCase):
 
     exec_documentation_example('outdated_relays.py')
 
-    self.assert_equal_unordered(OUTDATED_RELAYS_OUTPUT, stdout_mock.getvalue())
+    self.assertCountEqual(OUTDATED_RELAYS_OUTPUT.splitlines(), stdout_mock.getvalue().splitlines())
 
-  @patch('sys.stdout', new_callable = StringIO)
+  @patch('sys.stdout', new_callable = io.StringIO)
   @patch('stem.descriptor.remote.Query')
   @patch('stem.directory.Authority.from_cache')
   def test_compare_flags(self, authorities_mock, query_mock, stdout_mock):
-    if stem.prereq._is_python_26():
-      # example imports OrderedDict from collections which doesn't work under
-      # python 2.6
-
-      self.skipTest("(example doesn't support python 2.6)")
-      return
-
     authorities_mock().items.return_value = [('moria1', DIRECTORY_AUTHORITIES['moria1']), ('maatuska', DIRECTORY_AUTHORITIES['maatuska'])]
 
     fingerprint = [
@@ -277,9 +256,9 @@ class TestTutorialExamples(unittest.TestCase):
 
     exec_documentation_example('compare_flags.py')
 
-    self.assert_equal_unordered(COMPARE_FLAGS_OUTPUT, stdout_mock.getvalue())
+    self.assertCountEqual(COMPARE_FLAGS_OUTPUT.splitlines(), stdout_mock.getvalue().splitlines())
 
-  @patch('sys.stdout', new_callable = StringIO)
+  @patch('sys.stdout', new_callable = io.StringIO)
   @patch('stem.directory.Authority.from_cache')
   @patch('stem.descriptor.remote.DescriptorDownloader.query')
   def test_votes_by_bandwidth_authorities(self, query_mock, authorities_mock, stdout_mock):
@@ -310,9 +289,9 @@ class TestTutorialExamples(unittest.TestCase):
     query_mock.side_effect = [query1, query2, query3]
 
     exec_documentation_example('votes_by_bandwidth_authorities.py')
-    self.assert_equal_unordered(VOTES_BY_BANDWIDTH_AUTHORITIES_OUTPUT, stdout_mock.getvalue())
+    self.assertCountEqual(VOTES_BY_BANDWIDTH_AUTHORITIES_OUTPUT.splitlines(), stdout_mock.getvalue().splitlines())
 
-  @patch('sys.stdout', new_callable = StringIO)
+  @patch('sys.stdout', new_callable = io.StringIO)
   @patch('stem.descriptor.parse_file')
   @patch('stem.descriptor.remote.Query')
   def test_persisting_a_consensus(self, query_mock, parse_file_mock, stdout_mock):
diff --git a/test/unit/util/connection.py b/test/unit/util/connection.py
index 8721ff6d..d848c40b 100644
--- a/test/unit/util/connection.py
+++ b/test/unit/util/connection.py
@@ -5,25 +5,15 @@ Unit tests for the stem.util.connection functions.
 import io
 import platform
 import unittest
+import urllib.request
 
 import stem
 import stem.util.connection
 
-from stem.util.connection import Resolver, Connection
-
-try:
-  # account for urllib's change between python 2.x and 3.x
-  import urllib.request as urllib
-except ImportError:
-  import urllib2 as urllib
+from unittest.mock import Mock, patch
 
-try:
-  # added in python 3.3
-  from unittest.mock import Mock, patch
-except ImportError:
-  from mock import Mock, patch
+from stem.util.connection import Resolver, Connection
 
-URL_OPEN = 'urllib.request.urlopen' if stem.prereq.is_python_3() else 'urllib2.urlopen'
 URL = 'https://example.unit.test.url'
 
 NETSTAT_OUTPUT = """\
@@ -177,16 +167,16 @@ _tor     tor        15843   20* internet stream tcp 0x0 192.168.1.100:36174 -->
 
 
 class TestConnection(unittest.TestCase):
-  @patch(URL_OPEN)
+  @patch('urllib.request.urlopen')
   def test_download(self, urlopen_mock):
     urlopen_mock.return_value = io.BytesIO(b'hello')
 
     self.assertEqual(b'hello', stem.util.connection.download(URL))
     urlopen_mock.assert_called_with(URL, timeout = None)
 
-  @patch(URL_OPEN)
+  @patch('urllib.request.urlopen')
   def test_download_failure(self, urlopen_mock):
-    urlopen_mock.side_effect = urllib.URLError('boom')
+    urlopen_mock.side_effect = urllib.request.URLError('boom')
 
     try:
       stem.util.connection.download(URL)
@@ -195,12 +185,12 @@ class TestConnection(unittest.TestCase):
       self.assertEqual('Failed to download from https://example.unit.test.url (URLError): boom', str(exc))
       self.assertEqual(URL, exc.url)
       self.assertEqual('boom', exc.error.reason)
-      self.assertEqual(urllib.URLError, type(exc.error))
-      self.assertTrue('return urllib.urlopen(url, timeout = timeout).read()' in exc.stacktrace_str)
+      self.assertEqual(urllib.request.URLError, type(exc.error))
+      self.assertTrue('return urllib.request.urlopen(url, timeout = timeout).read()' in exc.stacktrace_str)
 
-  @patch(URL_OPEN)
+  @patch('urllib.request.urlopen')
   def test_download_retries(self, urlopen_mock):
-    urlopen_mock.side_effect = urllib.URLError('boom')
+    urlopen_mock.side_effect = urllib.request.URLError('boom')
 
     self.assertRaisesRegexp(IOError, 'boom', stem.util.connection.download, URL)
     self.assertEqual(1, urlopen_mock.call_count)
diff --git a/test/unit/util/proc.py b/test/unit/util/proc.py
index 6ee29136..2316f669 100644
--- a/test/unit/util/proc.py
+++ b/test/unit/util/proc.py
@@ -7,14 +7,11 @@ import unittest
 
 import test
 
+from unittest.mock import Mock, patch
+
 from stem.util import proc
 from stem.util.connection import Connection
 
-try:
-  from unittest.mock import Mock, patch
-except ImportError:
-  from mock import Mock, patch
-
 TITLE_LINE = b'sl  local_address rem_address   st tx_queue rx_queue tr tm->when retrnsmt  uid  timeout'
 
 TCP6_CONTENT = b"""\
diff --git a/test/unit/util/system.py b/test/unit/util/system.py
index b4fb81ea..32be337c 100644
--- a/test/unit/util/system.py
+++ b/test/unit/util/system.py
@@ -14,13 +14,9 @@ import unittest
 
 import stem.prereq
 
-from stem.util import system
+from unittest.mock import Mock, patch
 
-try:
-  # added in python 3.3
-  from unittest.mock import Mock, patch
-except ImportError:
-  from mock import Mock, patch
+from stem.util import system
 
 # Base responses for the pid_by_name tests. The 'success' and
 # 'multiple_results' entries are filled in by tests.
diff --git a/test/unit/version.py b/test/unit/version.py
index 3c21855c..abdb65c0 100644
--- a/test/unit/version.py
+++ b/test/unit/version.py
@@ -7,13 +7,9 @@ import unittest
 import stem.util.system
 import stem.version
 
-from stem.version import Version
+from unittest.mock import Mock, patch
 
-try:
-  # added in python 3.3
-  from unittest.mock import Mock, patch
-except ImportError:
-  from mock import Mock, patch
+from stem.version import Version
 
 VERSION_CMD_OUTPUT = """Mar 22 23:09:37.088 [notice] Tor v0.2.2.35 \
 (git-73ff13ab3cc9570d). This is experimental software. Do not rely on it for \
author	Damian Johnson <atagar@torproject.org>	2020-01-05 13:28:37 -0800
committer	Damian Johnson <atagar@torproject.org>	2020-01-05 13:28:37 -0800
commit	a396f57c3a55f34bb9f9d5976fc54fcc6561a8c4 (patch)
tree	f34f4715f5e7c5b2edf19558e0a683b984394d1b
parent	4e21371e88662992fa21bc1f845c05c16ccee4f4 (diff)
parent	bdd376bd9e25dcee54d43a47e10329d92f83cafd (diff)