2to3: Apply unicode fixer.

The unicode fixer strips the u from u'hi' and converts the unicode type
to str. The first won't work for Python 2 and instead we replace the u
prefix with the sixu function borrowed from the six compatibility
package. That function calls the unicode constructor with the
'unicode_escape' encoder so that the many tests using escaped unicode
characters like u'\u0900' will be handled correctly. That makes the
sixu function a bit different from the asunicode function currently in
numpy.compat and also provides a target that can be converted back to
the u prefix when support for Python 3.2 is dropped. Python 3.3
reintroduced the u prefix for compatibility.

The unicode fixer also replaces 'unicode' with 'str' as 'unicode' is no
longer a builtin in Python 3. For code compatibility, 'unicode' is
defined either as 'str' or 'unicode' in numpy.compat so that checks like

    if isinstance(x, unicode):
        ...

will work properly for all python versions.

Closes #3089.

1 files changed, 2 insertions, 1 deletions

diff --git a/numpy/lib/_iotools.py b/numpy/lib/_iotools.py
index 827adac02..aa39e25a1 100644
--- a/numpy/lib/_iotools.py
+++ b/numpy/lib/_iotools.py
@@ -11,7 +11,8 @@ import numpy.core.numeric as nx
 from numpy.compat import asbytes, bytes, asbytes_nested, long, basestring
 
 if sys.version_info[0] >= 3:
-    from builtins import bool, int, float, complex, object, unicode, str
+    from builtins import bool, int, float, complex, object,  str
+    unicode = str
 else:
     from __builtin__ import bool, int, float, complex, object, unicode, str