MAINT: Fix some pyflakes warnings in numpy/core/*.py

These fixes are not agressive as some of the code is complicated
and it is better to be careful.

The files numeric.py and numerictypes.py are not easily analysed
and the latter is self modifying. Pyflakes generates a number of
invalid warnings for those files.

9 files changed, 64 insertions, 75 deletions

diff --git a/numpy/core/_internal.py b/numpy/core/_internal.py
index b6af93d43..f8271d5ab 100644
--- a/numpy/core/_internal.py
+++ b/numpy/core/_internal.py
@@ -8,9 +8,8 @@ from __future__ import division, absolute_import, print_function
 
 import re
 import sys
-import warnings
 
-from numpy.compat import asbytes, bytes, basestring
+from numpy.compat import asbytes, basestring
 from .multiarray import dtype, array, ndarray
 import ctypes
 from .numerictypes import object_
@@ -561,7 +560,6 @@ def _dtype_from_pep3118(spec, byteorder='@', is_subdtype=False):
     this_explicit_name = False
     common_alignment = 1
     is_padding = False
-    last_offset = 0
 
     dummy_name_index = [0]
 
@@ -691,7 +689,6 @@ def _dtype_from_pep3118(spec, byteorder='@', is_subdtype=False):
                 raise RuntimeError("Duplicate field name '%s' in PEP3118 format"
                                    % name)
             fields[name] = (value, offset)
-            last_offset = offset
             if not this_explicit_name:
                 next_dummy_name()
 
diff --git a/numpy/core/defchararray.py b/numpy/core/defchararray.py
index e273007c9..e18f912d6 100644
--- a/numpy/core/defchararray.py
+++ b/numpy/core/defchararray.py
@@ -25,17 +25,18 @@ from numpy.core.multiarray import _vec_string
 from numpy.compat import asbytes, long
 import numpy
 
-__all__ = ['chararray',
-           'equal', 'not_equal', 'greater_equal', 'less_equal', 'greater', 'less',
-           'str_len', 'add', 'multiply', 'mod', 'capitalize', 'center', 'count',
-           'decode', 'encode', 'endswith', 'expandtabs', 'find', 'format',
-           'index', 'isalnum', 'isalpha', 'isdigit', 'islower', 'isspace',
-           'istitle', 'isupper', 'join', 'ljust', 'lower', 'lstrip',
-           'partition', 'replace', 'rfind', 'rindex', 'rjust', 'rpartition',
-           'rsplit', 'rstrip', 'split', 'splitlines', 'startswith', 'strip',
-           'swapcase', 'title', 'translate', 'upper', 'zfill',
-           'isnumeric', 'isdecimal',
-           'array', 'asarray']
+__all__ = [
+    'chararray', 'equal', 'not_equal', 'greater_equal', 'less_equal',
+    'greater', 'less', 'str_len', 'add', 'multiply', 'mod', 'capitalize',
+    'center', 'count', 'decode', 'encode', 'endswith', 'expandtabs',
+    'find', 'index', 'isalnum', 'isalpha', 'isdigit', 'islower', 'isspace',
+    'istitle', 'isupper', 'join', 'ljust', 'lower', 'lstrip', 'partition',
+    'replace', 'rfind', 'rindex', 'rjust', 'rpartition', 'rsplit',
+    'rstrip', 'split', 'splitlines', 'startswith', 'strip', 'swapcase',
+    'title', 'translate', 'upper', 'zfill', 'isnumeric', 'isdecimal',
+    'array', 'asarray'
+    ]
+
 
 _globalvar = 0
 if sys.version_info[0] >= 3:
diff --git a/numpy/core/function_base.py b/numpy/core/function_base.py
index 1e759e0c2..e50e1a505 100644
--- a/numpy/core/function_base.py
+++ b/numpy/core/function_base.py
@@ -3,7 +3,7 @@ from __future__ import division, absolute_import, print_function
 __all__ = ['logspace', 'linspace']
 
 from . import numeric as _nx
-from .numeric import array, result_type, NaN
+from .numeric import result_type, NaN
 
 
 def linspace(start, stop, num=50, endpoint=True, retstep=False, dtype=None):
diff --git a/numpy/core/memmap.py b/numpy/core/memmap.py
index 2e8b305d3..70d7b72b4 100644
--- a/numpy/core/memmap.py
+++ b/numpy/core/memmap.py
@@ -1,14 +1,11 @@
 from __future__ import division, absolute_import, print_function
 
-__all__ = ['memmap']
-
-import warnings
-import sys
-
 import numpy as np
 from .numeric import uint8, ndarray, dtype
 from numpy.compat import long, basestring
 
+__all__ = ['memmap']
+
 dtypedescr = dtype
 valid_filemodes = ["r", "c", "r+", "w+"]
 writeable_filemodes = ["r+", "w+"]
diff --git a/numpy/core/numeric.py b/numpy/core/numeric.py
index c31c5f75f..fd53b5c72 100644
--- a/numpy/core/numeric.py
+++ b/numpy/core/numeric.py
@@ -1,6 +1,5 @@
 from __future__ import division, absolute_import, print_function
 
-import os
 import sys
 import warnings
 import collections
@@ -21,30 +20,28 @@ else:
 loads = pickle.loads
 
 
-__all__ = ['newaxis', 'ndarray', 'flatiter', 'nditer', 'nested_iters', 'ufunc',
-           'arange', 'array', 'zeros', 'count_nonzero',
-           'empty', 'broadcast', 'dtype', 'fromstring', 'fromfile',
-           'frombuffer', 'int_asbuffer', 'where', 'argwhere', 'copyto',
-           'concatenate', 'fastCopyAndTranspose', 'lexsort', 'set_numeric_ops',
-           'can_cast', 'promote_types', 'min_scalar_type', 'result_type',
-           'asarray', 'asanyarray', 'ascontiguousarray', 'asfortranarray',
-           'isfortran', 'empty_like', 'zeros_like', 'ones_like',
-           'correlate', 'convolve', 'inner', 'dot', 'einsum', 'outer', 'vdot',
-           'alterdot', 'restoredot', 'roll', 'rollaxis', 'cross', 'tensordot',
-           'array2string', 'get_printoptions', 'set_printoptions',
-           'array_repr', 'array_str', 'set_string_function',
-           'little_endian', 'require',
-           'fromiter', 'array_equal', 'array_equiv',
-           'indices', 'fromfunction', 'isclose',
-           'load', 'loads', 'isscalar', 'binary_repr', 'base_repr',
-           'ones', 'identity', 'allclose', 'compare_chararrays', 'putmask',
-           'seterr', 'geterr', 'setbufsize', 'getbufsize',
-           'seterrcall', 'geterrcall', 'errstate', 'flatnonzero',
-           'Inf', 'inf', 'infty', 'Infinity',
-           'nan', 'NaN', 'False_', 'True_', 'bitwise_not',
-           'CLIP', 'RAISE', 'WRAP', 'MAXDIMS', 'BUFSIZE', 'ALLOW_THREADS',
-           'ComplexWarning', 'may_share_memory', 'full', 'full_like',
-           'matmul']
+__all__ = [
+    'newaxis', 'ndarray', 'flatiter', 'nditer', 'nested_iters', 'ufunc',
+    'arange', 'array', 'zeros', 'count_nonzero', 'empty', 'broadcast',
+    'dtype', 'fromstring', 'fromfile', 'frombuffer', 'int_asbuffer',
+    'where', 'argwhere', 'copyto', 'concatenate', 'fastCopyAndTranspose',
+    'lexsort', 'set_numeric_ops', 'can_cast', 'promote_types',
+    'min_scalar_type', 'result_type', 'asarray', 'asanyarray',
+    'ascontiguousarray', 'asfortranarray', 'isfortran', 'empty_like',
+    'zeros_like', 'ones_like', 'correlate', 'convolve', 'inner', 'dot',
+    'einsum', 'outer', 'vdot', 'alterdot', 'restoredot', 'roll',
+    'rollaxis', 'cross', 'tensordot', 'array2string', 'get_printoptions',
+    'set_printoptions', 'array_repr', 'array_str', 'set_string_function',
+    'little_endian', 'require', 'fromiter', 'array_equal', 'array_equiv',
+    'indices', 'fromfunction', 'isclose', 'load', 'loads', 'isscalar',
+    'binary_repr', 'base_repr', 'ones', 'identity', 'allclose',
+    'compare_chararrays', 'putmask', 'seterr', 'geterr', 'setbufsize',
+    'getbufsize', 'seterrcall', 'geterrcall', 'errstate', 'flatnonzero',
+    'Inf', 'inf', 'infty', 'Infinity', 'nan', 'NaN', 'False_', 'True_',
+    'bitwise_not', 'CLIP', 'RAISE', 'WRAP', 'MAXDIMS', 'BUFSIZE',
+    'ALLOW_THREADS', 'ComplexWarning', 'may_share_memory', 'full',
+    'full_like', 'matmul',
+    ]
 
 if sys.version_info[0] < 3:
     __all__.extend(['getbuffer', 'newbuffer'])
@@ -1281,7 +1278,7 @@ def tensordot(a, b, axes=2):
     bs = b.shape
     ndb = len(b.shape)
     equal = True
-    if (na != nb):
+    if na != nb:
         equal = False
     else:
         for k in range(na):
diff --git a/numpy/core/numerictypes.py b/numpy/core/numerictypes.py
index d8277beea..7dc6e0bd8 100644
--- a/numpy/core/numerictypes.py
+++ b/numpy/core/numerictypes.py
@@ -82,6 +82,18 @@ Exported symbols include:
 """
 from __future__ import division, absolute_import, print_function
 
+import types as _types
+import sys
+import numbers
+
+from numpy.compat import bytes, long
+from numpy.core.multiarray import (
+        typeinfo, ndarray, array, empty, dtype, datetime_data,
+        datetime_as_string, busday_offset, busday_count, is_busday,
+        busdaycalendar
+        )
+
+
 # we add more at the bottom
 __all__ = ['sctypeDict', 'sctypeNA', 'typeDict', 'typeNA', 'sctypes',
            'ScalarType', 'obj2sctype', 'cast', 'nbytes', 'sctype2char',
@@ -90,15 +102,6 @@ __all__ = ['sctypeDict', 'sctypeNA', 'typeDict', 'typeNA', 'sctypes',
            'busday_offset', 'busday_count', 'is_busday', 'busdaycalendar',
            ]
 
-from numpy.core.multiarray import (
-        typeinfo, ndarray, array, empty, dtype, datetime_data,
-        datetime_as_string, busday_offset, busday_count, is_busday,
-        busdaycalendar
-        )
-import types as _types
-import sys
-from numpy.compat import bytes, long
-import numbers
 
 # we don't export these for import *, but we do want them accessible
 # as numerictypes.bool, etc.
@@ -328,15 +331,10 @@ def _add_aliases():
             sctypeNA[char] = na_name
 _add_aliases()
 
-# Integers handled so that
-# The int32, int64 types should agree exactly with
-#  PyArray_INT32, PyArray_INT64 in C
-# We need to enforce the same checking as is done
-#  in arrayobject.h where the order of getting a
-#  bit-width match is:
-#       long, longlong, int, short, char
-#   for int8, int16, int32, int64, int128
-
+# Integers are handled so that the int32 and int64 types should agree
+# exactly with NPY_INT32, NPY_INT64. We need to enforce the same checking
+# as is done in arrayobject.h where the order of getting a bit-width match
+# is long, longlong, int, short, char.
 def _add_integer_aliases():
     _ctypes = ['LONG', 'LONGLONG', 'INT', 'SHORT', 'BYTE']
     for ctype in _ctypes:
@@ -960,6 +958,7 @@ def _register_types():
     numbers.Integral.register(integer)
     numbers.Complex.register(inexact)
     numbers.Real.register(floating)
+
 _register_types()
 
 def find_common_type(array_types, scalar_types):
diff --git a/numpy/core/setup.py b/numpy/core/setup.py
index ac797562d..9221bd2c4 100644
--- a/numpy/core/setup.py
+++ b/numpy/core/setup.py
@@ -3,11 +3,9 @@ from __future__ import division, print_function
 import imp
 import os
 import sys
-import shutil
 import pickle
 import copy
 import warnings
-import re
 from os.path import join
 from numpy.distutils import log
 from distutils.dep_util import newer
@@ -381,7 +379,7 @@ def visibility_define(config):
 
 def configuration(parent_package='',top_path=None):
     from numpy.distutils.misc_util import Configuration, dot_join
-    from numpy.distutils.system_info import get_info, default_lib_dirs
+    from numpy.distutils.system_info import get_info
 
     config = Configuration('core', parent_package, top_path)
     local_dir = config.local_path
diff --git a/numpy/core/setup_common.py b/numpy/core/setup_common.py
index c7bb8688c..c923b6d91 100644
--- a/numpy/core/setup_common.py
+++ b/numpy/core/setup_common.py
@@ -2,12 +2,10 @@ from __future__ import division, absolute_import, print_function
 
 # Code common to build tools
 import sys
-from os.path import join
 import warnings
 import copy
 import binascii
 
-from distutils.ccompiler import CompileError
 
 #-------------------
 # Versioning support
@@ -54,11 +52,13 @@ def is_released(config):
     return True
 
 def get_api_versions(apiversion, codegen_dir):
-    """Return current C API checksum and the recorded checksum for the given
-    version of the C API version."""
-    api_files = [join(codegen_dir, 'numpy_api_order.txt'),
-                 join(codegen_dir, 'ufunc_api_order.txt')]
+    """
+    Return current C API checksum and the recorded checksum.
+
+    Return current C API checksum and the recorded checksum for the given
+    version of the C API version.
 
+    """
     # Compute the hash of the current API as defined in the .txt files in
     # code_generators
     sys.path.insert(0, codegen_dir)
diff --git a/numpy/core/shape_base.py b/numpy/core/shape_base.py
index 50c46f38e..0dd2e164a 100644
--- a/numpy/core/shape_base.py
+++ b/numpy/core/shape_base.py
@@ -4,7 +4,7 @@ __all__ = ['atleast_1d', 'atleast_2d', 'atleast_3d', 'vstack', 'hstack',
            'stack']
 
 from . import numeric as _nx
-from .numeric import array, asanyarray, newaxis
+from .numeric import asanyarray, newaxis
 
 def atleast_1d(*arys):
     """