[flake8] whitespace changes

E226 whitespace around operator
E251 unexpected spaces around keyword / parameter equals
E261 at least two spaces before inline comment
E271 multiple spaces after keyword
E302 expected 2 blank lines, found 1
E303 too many blank lines
E305 expected 2 blank lines after class or function definition, found 1
E306 expected 1 blank line before a nested definition, found 0

Also:
* Ignored flake8 for now in test_*, there are incompatible practices there.
* Marked a few errors as temporarily ignored until we resolve them by pull
  requests.
* Added flake8 to be executed on Travis CI under Python 3.6

Author: ambv

.travis.yml

@@ -10,5 +10,9 @@ python:
   - "3.2"
   - "2.7"
 
+install:
+- pip install -r test-requirements.txt
+
 script:
   - export PYTHONPATH=`python -c "import sys; print('python2' if sys.version.startswith('2') else 'src')"`; py.test $PYTHONPATH
+  - if [[ $TRAVIS_PYTHON_VERSION == '3.6' ]]; then flake8; fi

python2/typing.py

@@ -86,6 +86,7 @@ def _qualname(x):
         # Fall back to just name.
         return x.__name__
 
+
 def _trim_name(nm):
     if nm.startswith('_') and nm not in ('_TypeAlias',
                     '_ForwardRef', '_TypingBase', '_FinalTypingBase'):
@@ -245,7 +246,6 @@ class _TypeAlias(_TypingBase):
 
     __slots__ = ('name', 'type_var', 'impl_type', 'type_checker')
 
-
     def __init__(self, name, type_var, impl_type, type_checker):
         """Initializer.
 
@@ -419,6 +419,7 @@ def __eq__(self, other):
             return self.__type__ == other.__type__
         return self is other
 
+
 ClassVar = _ClassVar(_root=True)
 
 
@@ -919,7 +920,7 @@ def _next_in_mro(cls):
     # Look for the last occurrence of Generic or Generic[...].
     for i, c in enumerate(cls.__mro__[:-1]):
         if isinstance(c, GenericMeta) and _gorg(c) is Generic:
-            next_in_mro = cls.__mro__[i+1]
+            next_in_mro = cls.__mro__[i + 1]
     return next_in_mro
 
 
@@ -1329,7 +1330,7 @@ def __getitem__(self, parameters):
         with hashable arguments to improve speed.
         """
 
-        if  self.__origin__ is not None or not _geqv(self, Callable):
+        if self.__origin__ is not None or not _geqv(self, Callable):
             return super(CallableMeta, self).__getitem__(parameters)
         if not isinstance(parameters, tuple) or len(parameters) != 2:
             raise TypeError("Callable must be used as "
@@ -1432,7 +1433,7 @@ def no_type_check(arg):
                 no_type_check(obj)
     try:
         arg.__no_type_check__ = True
-    except TypeError: # built-in classes
+    except TypeError:  # built-in classes
         pass
     return arg
 
@@ -1696,6 +1697,7 @@ def __new__(cls, *args, **kwds):
                             "use list() instead")
         return _generic_new(list, cls, *args, **kwds)
 
+
 class Deque(collections.deque, MutableSequence[T]):
     __slots__ = ()
     __extra__ = collections.deque
@@ -1706,6 +1708,7 @@ def __new__(cls, *args, **kwds):
                             "use deque() instead")
         return _generic_new(collections.deque, cls, *args, **kwds)
 
+
 class Set(set, MutableSet[T]):
     __slots__ = ()
     __extra__ = set
@@ -1932,23 +1935,23 @@ def isatty(self):
         pass
 
     @abstractmethod
-    def read(self, n = -1):
+    def read(self, n=-1):
         pass
 
     @abstractmethod
     def readable(self):
         pass
 
     @abstractmethod
-    def readline(self, limit = -1):
+    def readline(self, limit=-1):
         pass
 
     @abstractmethod
-    def readlines(self, hint = -1):
+    def readlines(self, hint=-1):
         pass
 
     @abstractmethod
-    def seek(self, offset, whence = 0):
+    def seek(self, offset, whence=0):
         pass
 
     @abstractmethod
@@ -1960,7 +1963,7 @@ def tell(self):
         pass
 
     @abstractmethod
-    def truncate(self, size = None):
+    def truncate(self, size=None):
         pass
 
     @abstractmethod
@@ -2036,6 +2039,7 @@ class io(object):
     TextIO = TextIO
     BinaryIO = BinaryIO
 
+
 io.__name__ = __name__ + b'.io'
 sys.modules[io.__name__] = io
 
@@ -2053,5 +2057,6 @@ class re(object):
     Pattern = Pattern
     Match = Match
 
+
 re.__name__ = __name__ + b'.re'
 sys.modules[re.__name__] = re

src/typing.py

@@ -631,6 +631,7 @@ def _tp_cache(func):
 
     cached = functools.lru_cache()(func)
     _cleanups.append(cached.cache_clear)
+
     @functools.wraps(func)
     def inner(*args, **kwds):
         try:
@@ -840,7 +841,7 @@ def _next_in_mro(cls):
     # Look for the last occurrence of Generic or Generic[...].
     for i, c in enumerate(cls.__mro__[:-1]):
         if isinstance(c, GenericMeta) and _gorg(c) is Generic:
-            next_in_mro = cls.__mro__[i+1]
+            next_in_mro = cls.__mro__[i + 1]
     return next_in_mro
 
 
@@ -1252,7 +1253,7 @@ def __getitem__(self, parameters):
         with hashable arguments to improve speed.
         """
 
-        if  self.__origin__ is not None or not _geqv(self, Callable):
+        if self.__origin__ is not None or not _geqv(self, Callable):
             return super().__getitem__(parameters)
         if not isinstance(parameters, tuple) or len(parameters) != 2:
             raise TypeError("Callable must be used as "
@@ -1280,7 +1281,7 @@ def __getitem_inner__(self, parameters):
         return super().__getitem__(parameters)
 
 
-class Callable(extra=collections_abc.Callable, metaclass = CallableMeta):
+class Callable(extra=collections_abc.Callable, metaclass=CallableMeta):
     """Callable type; Callable[[int], str] is a function of (int) -> str.
 
     The subscription syntax must always be used with exactly two
@@ -1485,7 +1486,7 @@ def no_type_check(arg):
                 no_type_check(obj)
     try:
         arg.__no_type_check__ = True
-    except TypeError: # built-in classes
+    except TypeError:  # built-in classes
         pass
     return arg
 
@@ -1771,6 +1772,7 @@ class Mapping(Sized, Iterable[KT], Container[KT], Generic[KT, VT_co],
 class MutableMapping(Mapping[KT, VT], extra=collections_abc.MutableMapping):
     __slots__ = ()
 
+
 if hasattr(collections_abc, 'Reversible'):
     if hasattr(collections_abc, 'Collection'):
         class Sequence(Reversible[T_co], Collection[T_co],
@@ -1804,6 +1806,7 @@ def __new__(cls, *args, **kwds):
                             "use list() instead")
         return _generic_new(list, cls, *args, **kwds)
 
+
 class Deque(collections.deque, MutableSequence[T], extra=collections.deque):
 
     __slots__ = ()
@@ -1814,6 +1817,7 @@ def __new__(cls, *args, **kwds):
                             "use deque() instead")
         return _generic_new(collections.deque, cls, *args, **kwds)
 
+
 class Set(set, MutableSet[T], extra=set):
 
     __slots__ = ()
@@ -1871,6 +1875,7 @@ def __new__(cls, *args, **kwds):
                             "use dict() instead")
         return _generic_new(dict, cls, *args, **kwds)
 
+
 class DefaultDict(collections.defaultdict, MutableMapping[KT, VT],
                   extra=collections.defaultdict):
 
@@ -1882,6 +1887,7 @@ def __new__(cls, *args, **kwds):
                             "use collections.defaultdict() instead")
         return _generic_new(collections.defaultdict, cls, *args, **kwds)
 
+
 # Determine what base class to use for Generator.
 if hasattr(collections_abc, 'Generator'):
     # Sufficiently recent versions of 3.5 have a Generator ABC.
@@ -1901,6 +1907,7 @@ def __new__(cls, *args, **kwds):
                             "create a subclass instead")
         return _generic_new(_G_base, cls, *args, **kwds)
 
+
 if hasattr(collections_abc, 'AsyncGenerator'):
     class AsyncGenerator(AsyncIterator[T_co], Generic[T_co, T_contra],
                          extra=collections_abc.AsyncGenerator):
@@ -1984,6 +1991,7 @@ def __new__(cls, typename, bases, ns):
         nm_tpl._field_defaults = defaults_dict
         return nm_tpl
 
+
 class NamedTuple(metaclass=NamedTupleMeta):
     """Typed version of namedtuple.
 
@@ -2207,6 +2215,7 @@ class io:
     TextIO = TextIO
     BinaryIO = BinaryIO
 
+
 io.__name__ = __name__ + '.io'
 sys.modules[io.__name__] = io
 
@@ -2224,5 +2233,6 @@ class re:
     Pattern = Pattern
     Match = Match
 
+
 re.__name__ = __name__ + '.re'
 sys.modules[re.__name__] = re

test-requirements.txt

@@ -0,0 +1,6 @@
+flake8; python_version >= '3.6'
+flake8-bugbear; python_version >= '3.6'
+flake8-pyi; python_version >= '3.6'
+pytest>=2.8
+pytest-xdist>=1.13
+pytest-cov>=2.4.0

tox.ini

@@ -8,8 +8,21 @@ commands = python -m unittest discover
 [testenv:py27]
 changedir = python2
 
-[pep8]
-ignore = E129,E226,E251
-
 [flake8]
-ignore = DW12,E226,E251,F401,F811
+# fake builtins for python2/*
+builtins = basestring, unicode
+ignore =
+  # temporary ignores until we sort it out
+  B007,
+  E128,
+  E129,
+  E501,
+  E711,
+  W503,
+  # irrelevant plugins
+  B3,
+  DW12
+exclude =
+  # tests have more relaxed formatting rules
+  python2/test_typing.py,
+  src/test_typing.py