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, 4 insertions, 9 deletions

diff --git a/numpy/polynomial/polytemplate.py b/numpy/polynomial/polytemplate.py
index 7d67c914c..adf32170f 100644
--- a/numpy/polynomial/polytemplate.py
+++ b/numpy/polynomial/polytemplate.py
@@ -9,21 +9,16 @@ creating additional specific polynomial classes (e.g., Legendre, Jacobi,
 etc.) in the future, such that all these classes will have a common API.
 
 """
-from __future__ import division
+from __future__ import division, absolute_import
 
 import string
 import sys
 
-if sys.version_info[0] >= 3:
-    rel_import = "from . import"
-else:
-    rel_import = "import"
-
 polytemplate = string.Template('''
-from __future__ import division
+from __future__ import division, absolute_import
 import numpy as np
 import warnings
-REL_IMPORT polyutils as pu
+from . import polyutils as pu
 
 class $name(pu.PolyBase) :
     """A $name series class.
@@ -918,4 +913,4 @@ class $name(pu.PolyBase) :
         """
         return series.convert(domain, $name, window)
 
-'''.replace('REL_IMPORT', rel_import))
+''')