2to3: Apply `imports` fixer.

The `imports` fixer deals with the standard packages that have been
renamed, removed, or methods that have moved.

cPickle      -- removed, use pickle
commands     -- removed, getoutput, getstatusoutput moved to subprocess
urlparse     -- removed, urlparse moved to urllib.parse
cStringIO    -- removed, use StringIO or io.StringIO
copy_reg     -- renamed copyreg
_winreg      -- renamed winreg
ConfigParser -- renamed configparser
__builtin__  -- renamed builtins

In the case of `cPickle`, it is imported as `pickle` when python < 3 and
performance may be a consideration, but otherwise plain old `pickle` is
used.

Dealing with `StringIO` is a bit tricky. There is an `io.StringIO`
function in the `io` module, available since Python 2.6, but it expects
unicode whereas `StringIO.StringIO` expects ascii. The Python 3
equivalent is then `io.BytesIO`. What I have done here is used BytesIO
for anything that is emulating a file for testing purposes. That is more
explicit than using a redefined StringIO as was done before we dropped
support for Python 2.4 and 2.5.

Closes #3180.

1 files changed, 10 insertions, 5 deletions

diff --git a/numpy/distutils/tests/test_exec_command.py b/numpy/distutils/tests/test_exec_command.py
index 11f262369..3e85fcd3e 100644
--- a/numpy/distutils/tests/test_exec_command.py
+++ b/numpy/distutils/tests/test_exec_command.py
@@ -2,11 +2,16 @@ from __future__ import division, absolute_import
 
 import os
 import sys
-import StringIO
 from tempfile import TemporaryFile
 
 from numpy.distutils import exec_command
 
+# In python 3 stdout, stderr are text (unicode compliant) devices, so to
+# emulate them import StringIO from the io module.
+if sys.version_info[0] >= 3:
+    from io import StringIO
+else:
+    from StringIO import StringIO
 
 class redirect_stdout(object):
     """Context manager to redirect stdout for exec_command test."""
@@ -62,26 +67,26 @@ def test_exec_command_stdout():
     # both that the special case works and that the generic code works.
 
     # Test posix version:
-    with redirect_stdout(StringIO.StringIO()):
+    with redirect_stdout(StringIO()):
         with redirect_stderr(TemporaryFile()):
             exec_command.exec_command("cd '.'")
 
     if os.name == 'posix':
         # Test general (non-posix) version:
         with emulate_nonposix():
-            with redirect_stdout(StringIO.StringIO()):
+            with redirect_stdout(StringIO()):
                 with redirect_stderr(TemporaryFile()):
                     exec_command.exec_command("cd '.'")
 
 def test_exec_command_stderr():
     # Test posix version:
     with redirect_stdout(TemporaryFile(mode='w+')):
-        with redirect_stderr(StringIO.StringIO()):
+        with redirect_stderr(StringIO()):
             exec_command.exec_command("cd '.'")
 
     if os.name == 'posix':
         # Test general (non-posix) version:
         with emulate_nonposix():
             with redirect_stdout(TemporaryFile()):
-                with redirect_stderr(StringIO.StringIO()):
+                with redirect_stderr(StringIO()):
                     exec_command.exec_command("cd '.'")