A few style changes originally done in the distutils2 repo

Lib/packaging/command/build_scripts.py

@@ -3,7 +3,7 @@
 import os
 import re
 import sysconfig
-import tokenize
+from tokenize import detect_encoding
 
 from packaging.command.cmd import Command
 from packaging.util import convert_path, newer
@@ -83,7 +83,7 @@ class build_scripts(Command, Mixin2to3):
                     raise
                 f = None
             else:
-                encoding, lines = tokenize.detect_encoding(f.readline)
+                encoding, lines = detect_encoding(f.readline)
                 f.seek(0)
                 first_line = f.readline()
                 if not first_line:

Lib/packaging/create.py

@@ -25,10 +25,11 @@ import sys
 import glob
 import shutil
 import sysconfig
-import tokenize
 from hashlib import md5
 from textwrap import dedent
+from tokenize import detect_encoding
 from configparser import RawConfigParser
+
 # importing this with an underscore as it should be replaced by the
 # dict form or another structures for all purposes
 from packaging._trove import all_classifiers as _CLASSIFIERS_LIST
@@ -111,7 +112,7 @@ def load_setup():
     been loaded before, because we are monkey patching its setup function with
     a particular one"""
     with open("setup.py", "rb") as f:
-        encoding, lines = tokenize.detect_encoding(f.readline)
+        encoding, lines = detect_encoding(f.readline)
     with open("setup.py", encoding=encoding) as f:
         imp.load_module("setup", f, "setup.py", (".py", "r", imp.PY_SOURCE))
 

Lib/shutil.py

@@ -391,7 +391,7 @@ def _make_tarball(base_name, base_dir, compress="gzip", verbose=0, dry_run=0,
         compress_ext['bzip2'] = '.bz2'
 
     # flags for compression program, each element of list will be an argument
-    if compress is not None and compress not in compress_ext.keys():
+    if compress is not None and compress not in compress_ext:
         raise ValueError("bad value for 'compress', or compression format not "
                          "supported : {0}".format(compress))
 

Lib/test/test_sysconfig.py

@@ -39,7 +39,7 @@ class TestSysConfig(unittest.TestCase):
         self._config_vars = copy(sysconfig._CONFIG_VARS)
         self._added_envvars = []
         self._changed_envvars = []
-        for var in ('MACOSX_DEPLOYMENT_TARGET', 'Path'):
+        for var in ('MACOSX_DEPLOYMENT_TARGET', 'PATH'):
             if var in os.environ:
                 self._changed_envvars.append((var, os.environ[var]))
             else:
@@ -87,21 +87,19 @@ class TestSysConfig(unittest.TestCase):
         scheme = get_paths()
         default_scheme = _get_default_scheme()
         wanted = _expand_vars(default_scheme, None)
-        wanted = list(wanted.items())
-        wanted.sort()
-        scheme = list(scheme.items())
-        scheme.sort()
+        wanted = sorted(wanted.items())
+        scheme = sorted(scheme.items())
         self.assertEqual(scheme, wanted)
 
     def test_get_path(self):
-        # xxx make real tests here
+        # XXX make real tests here
         for scheme in _SCHEMES:
             for name in _SCHEMES[scheme]:
                 res = get_path(name, scheme)
 
     def test_get_config_vars(self):
         cvars = get_config_vars()
-        self.assertTrue(isinstance(cvars, dict))
+        self.assertIsInstance(cvars, dict)
         self.assertTrue(cvars)
 
     def test_get_platform(self):
@@ -236,8 +234,8 @@ class TestSysConfig(unittest.TestCase):
         # On Windows, the EXE needs to know where pythonXY.dll is at so we have
         # to add the directory to the path.
         if sys.platform == "win32":
-            os.environ["Path"] = "{};{}".format(
-                os.path.dirname(sys.executable), os.environ["Path"])
+            os.environ["PATH"] = "{};{}".format(
+                os.path.dirname(sys.executable), os.environ["PATH"])
 
         # Issue 7880
         def get(python):