Added the pep8 test to travis. All the warnings are disabled and only a few...

Added the pep8 test to travis. All the warnings are disabled and only a few error checks are enabled.

.travis.yml

@@ -44,6 +44,10 @@ env:
 
 matrix:
   include:
+    - python: 3.7
+      dist: xenial    # Required for Python 3.7
+      sudo: required  # travis-ci/travis-ci#9069
+      env: TEST_CODE_STYLE=1
     - python: 3.7
       dist: xenial    # Required for Python 3.7
       sudo: required  # travis-ci/travis-ci#9069
@@ -144,9 +148,14 @@ install:
 before_script: ccache -s || true
 
 script:
+  - if [ "$TEST_CODE_STYLE" = "1" ]; then
+      STYLE_ARGS="--no-unit --no-doctest --no-file --no-pyregr --no-examples";
+    else
+      STYLE_ARGS=--no-code-style;
+    fi
   - PYTHON_DBG="python$( python -c 'import sys; print("%d.%d" % sys.version_info[:2])' )-dbg"
-  - if $PYTHON_DBG -V >&2; then CFLAGS="-O0 -ggdb" $PYTHON_DBG runtests.py -vv Debugger --backends=$BACKEND; fi
+  - if $PYTHON_DBG -V >&2; then CFLAGS="-O0 -ggdb" $PYTHON_DBG runtests.py -vv $STYLE_ARGS Debugger --backends=$BACKEND; fi
   - if [ "$BACKEND" = "cpp" -a -n "${TRAVIS_PYTHON_VERSION##2.6*}" ]; then pip install pythran; fi
   - if [ "$BACKEND" = "c" -a -n "${TRAVIS_PYTHON_VERSION##2*}" ]; then pip install mypy; fi
   - CFLAGS="-O2 -ggdb -Wall -Wextra $(python -c 'import sys; print("-fno-strict-aliasing" if sys.version_info[0] == 2 else "")')" python setup.py build_ext -i
-  - CFLAGS="-O0 -ggdb -Wall -Wextra" python runtests.py -vv -x Debugger --backends=$BACKEND -j7
+  - CFLAGS="-O0 -ggdb -Wall -Wextra" python runtests.py -vv $STYLE_ARGS -x Debugger --backends=$BACKEND -j7

Cython/Build/Dependencies.py

@@ -230,7 +230,7 @@ class DistutilsInfo(object):
                     break
                 line = line[1:].lstrip()
                 kind = next((k for k in ("distutils:","cython:") if line.startswith(k)), None)
-                if not kind is None:
+                if kind is not None:
                     key, _, value = [s.strip() for s in line[len(kind):].partition('=')]
                     type = distutils_settings.get(key, None)
                     if line.startswith("cython:") and type is None: continue

Cython/Compiler/ModuleNode.py

@@ -113,7 +113,7 @@ class ModuleNode(Nodes.Node, Nodes.BlockNode):
             env.doc = self.doc = None
         elif Options.embed_pos_in_docstring:
             env.doc = EncodedString(u'File: %s (starting at line %s)' % Nodes.relative_position(self.pos))
-            if not self.doc is None:
+            if self.doc is not None:
                 env.doc = EncodedString(env.doc + u'\n' + self.doc)
                 env.doc.encoding = self.doc.encoding
         else:

Demos/overflow_perf_run.py

@@ -16,7 +16,7 @@ def run_tests(N):
         print(func.__name__)
         for type in ['int', 'unsigned int', 'long long', 'unsigned long long', 'object']:
             if func == most_orthogonal:
-                if type == 'object' or np == None:
+                if type == 'object' or np is None:
                     continue
                 type_map = {'int': 'int32', 'unsigned int': 'uint32', 'long long': 'int64', 'unsigned long long': 'uint64'}
                 shape = N, 3

runtests.py

@@ -1446,6 +1446,22 @@ class CythonPyregrTestCase(CythonRunTestCase):
         run_forked_test(result, run_test, self.shortDescription(), self.fork)
 
 
+class TestCodeFormat(unittest.TestCase):
+
+    def __init__(self, cython_dir):
+        self.cython_dir = cython_dir
+        unittest.TestCase.__init__(self)
+
+    def runTest(self):
+        import pycodestyle
+        config_file = os.path.join(self.cython_dir, "tox.ini")
+        paths = glob.glob(os.path.join(self.cython_dir, "**/*.py"), recursive=True)
+        style = pycodestyle.StyleGuide(config_file=config_file)
+        print("")  # Fix the first line of the report.
+        result = style.check_files(paths)
+        self.assertEqual(result.total_errors, 0, "Found code style errors.")
+
+
 include_debugger = IS_CPYTHON
 
 
@@ -1868,6 +1884,9 @@ def main():
     parser.add_option("--no-examples", dest="examples",
                       action="store_false", default=True,
                       help="Do not run the documentation tests in the examples directory.")
+    parser.add_option("--no-code-style", dest="code_style",
+                      action="store_false", default=True,
+                      help="Do not run the code style (PEP8) checks.")
     parser.add_option("--cython-only", dest="cython_only",
                       action="store_true", default=False,
                       help="only compile pyx to c, do not run C compiler or run the tests")
@@ -2214,6 +2233,9 @@ def runtests(options, cmd_args, coverage=None):
             sys.stderr.write("Including CPython regression tests in %s\n" % sys_pyregr_dir)
             test_suite.addTest(filetests.handle_directory(sys_pyregr_dir, 'pyregr'))
 
+    if options.code_style and options.shard_num <= 0:
+        test_suite.addTest(TestCodeFormat(options.cython_dir))
+
     if xml_output_dir:
         from Cython.Tests.xmlrunner import XMLTestRunner
         if not os.path.exists(xml_output_dir):

test-requirements.txt

 numpy
 jupyter
 coverage
+pycodestyle

tox.ini

@@ -10,3 +10,9 @@ envlist = py26, py27, py32, py33, py34, pypy
 setenv = CFLAGS=-O0 -ggdb
 commands =
     {envpython} runtests.py -vv
+
+[pycodestyle]
+ignore = W, E
+select = E711, E714
+max-line-length = 300
+format = pylint