2to3: Use absolute imports.

The new import `absolute_import` is added the `from __future__ import`
statement and The 2to3 `import` fixer is run to make the imports
compatible. There are several things that need to be dealt with to make
this work.

1) Files meant to be run as scripts run in a different environment than
files imported as part of a package, and so changes to those files need
to be skipped. The affected script files are:

    * all setup.py files
    * numpy/core/code_generators/generate_umath.py
    * numpy/core/code_generators/generate_numpy_api.py
    * numpy/core/code_generators/generate_ufunc_api.py

2) Some imported modules are not available as they are created during
the build process and consequently 2to3 is unable to handle them
correctly. Files that import those modules need a bit of extra work.
The affected files are:

    * core/__init__.py,
    * core/numeric.py,
    * core/_internal.py,
    * core/arrayprint.py,
    * core/fromnumeric.py,
    * numpy/__init__.py,
    * lib/npyio.py,
    * lib/function_base.py,
    * fft/fftpack.py,
    * random/__init__.py

Closes #3172

1 files changed, 6 insertions, 6 deletions

diff --git a/numpy/core/_internal.py b/numpy/core/_internal.py
index 6b448528e..ae7a81ca8 100644
--- a/numpy/core/_internal.py
+++ b/numpy/core/_internal.py
@@ -4,7 +4,7 @@ A place for code to be called from core C-code.
 Some things are more easily handled Python.
 
 """
-from __future__ import division
+from __future__ import division, absolute_import
 
 import re
 import sys
@@ -18,7 +18,7 @@ else:
     _nbo = asbytes('>')
 
 def _makenames_list(adict, align):
-    from multiarray import dtype
+    from .multiarray import dtype
     allfields = []
     fnames = adict.keys()
     for fname in fnames:
@@ -52,7 +52,7 @@ def _makenames_list(adict, align):
 #  a dictionary without "names" and "formats"
 #  fields is used as a data-type descriptor.
 def _usefields(adict, align):
-    from multiarray import dtype
+    from .multiarray import dtype
     try:
         names = adict[-1]
     except KeyError:
@@ -130,7 +130,7 @@ def _array_descr(descriptor):
 # so don't remove the name here, or you'll
 # break backward compatibilty.
 def _reconstruct(subtype, shape, dtype):
-    from multiarray import ndarray
+    from .multiarray import ndarray
     return ndarray.__new__(subtype, shape, dtype)
 
 
@@ -194,7 +194,7 @@ def _commastring(astr):
     return result
 
 def _getintp_ctype():
-    from multiarray import dtype
+    from .multiarray import dtype
     val = _getintp_ctype.cache
     if val is not None:
         return val
@@ -290,7 +290,7 @@ def _newnames(datatype, order):
 # Given an array with fields and a sequence of field names
 # construct a new array with just those fields copied over
 def _index_fields(ary, fields):
-    from multiarray import empty, dtype, array
+    from .multiarray import empty, dtype, array
     dt = ary.dtype
 
     names = [name for name in fields if name in dt.names]