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.

6 files changed, 37 insertions, 21 deletions

diff --git a/numpy/distutils/cpuinfo.py b/numpy/distutils/cpuinfo.py
index 1e2d9379c..aaf642691 100644
--- a/numpy/distutils/cpuinfo.py
+++ b/numpy/distutils/cpuinfo.py
@@ -18,10 +18,12 @@ __all__ = ['cpu']
 
 import sys, re, types
 import os
-if sys.version_info[0] < 3:
-    from commands import getstatusoutput
-else:
+
+if sys.version_info[0] >= 3:
     from subprocess import getstatusoutput
+else:
+    from commands import getstatusoutput
+
 import warnings
 import platform
 
@@ -488,25 +490,29 @@ class Win32CPUInfo(CPUInfoBase):
         info = []
         try:
             #XXX: Bad style to use so long `try:...except:...`. Fix it!
-            import _winreg
+            if sys.version_info[0] >= 3:
+                import winreg
+            else:
+                import _winreg as winreg
+
             prgx = re.compile(r"family\s+(?P<FML>\d+)\s+model\s+(?P<MDL>\d+)"\
                               "\s+stepping\s+(?P<STP>\d+)",re.IGNORECASE)
-            chnd=_winreg.OpenKey(_winreg.HKEY_LOCAL_MACHINE, self.pkey)
+            chnd=winreg.OpenKey(winreg.HKEY_LOCAL_MACHINE, self.pkey)
             pnum=0
             while 1:
                 try:
-                    proc=_winreg.EnumKey(chnd,pnum)
-                except _winreg.error:
+                    proc=winreg.EnumKey(chnd,pnum)
+                except winreg.error:
                     break
                 else:
                     pnum+=1
                     info.append({"Processor":proc})
-                    phnd=_winreg.OpenKey(chnd,proc)
+                    phnd=winreg.OpenKey(chnd,proc)
                     pidx=0
                     while True:
                         try:
-                            name,value,vtpe=_winreg.EnumValue(phnd,pidx)
-                        except _winreg.error:
+                            name,value,vtpe=winreg.EnumValue(phnd,pidx)
+                        except winreg.error:
                             break
                         else:
                             pidx=pidx+1
diff --git a/numpy/distutils/mingw32ccompiler.py b/numpy/distutils/mingw32ccompiler.py
index 0505309fa..ed0dc0d4e 100644
--- a/numpy/distutils/mingw32ccompiler.py
+++ b/numpy/distutils/mingw32ccompiler.py
@@ -10,7 +10,6 @@ Support code for building Python extensions on Windows.
 from __future__ import division, absolute_import
 
 import os
-import subprocess
 import sys
 import subprocess
 import re
diff --git a/numpy/distutils/misc_util.py b/numpy/distutils/misc_util.py
index f526557d6..0c88e0ae4 100644
--- a/numpy/distutils/misc_util.py
+++ b/numpy/distutils/misc_util.py
@@ -2125,9 +2125,13 @@ def get_info(pkgname, dirs=None):
     return info
 
 def is_bootstrapping():
-    import __builtin__
+    if sys.version_info[0] >= 3:
+        import builtins
+    else:
+        import __builtin__ as builtins
+
     try:
-        __builtin__.__NUMPY_SETUP__
+        builtins.__NUMPY_SETUP__
         return True
     except AttributeError:
         return False
diff --git a/numpy/distutils/npy_pkg_config.py b/numpy/distutils/npy_pkg_config.py
index 2dacbbc70..a0d75670b 100644
--- a/numpy/distutils/npy_pkg_config.py
+++ b/numpy/distutils/npy_pkg_config.py
@@ -1,13 +1,14 @@
 from __future__ import division, absolute_import
 
 import sys
+import re
+import os
+import shlex
+
 if sys.version_info[0] < 3:
     from ConfigParser import SafeConfigParser, NoOptionError
 else:
     from configparser import ConfigParser, SafeConfigParser, NoOptionError
-import re
-import os
-import shlex
 
 __all__ = ['FormatError', 'PkgNotFound', 'LibraryInfo', 'VariableSet',
         'read_config', 'parse_flags']
diff --git a/numpy/distutils/system_info.py b/numpy/distutils/system_info.py
index 68ad926e3..ff32daf69 100644
--- a/numpy/distutils/system_info.py
+++ b/numpy/distutils/system_info.py
@@ -118,6 +118,7 @@ import re
 import copy
 import warnings
 from glob import glob
+
 if sys.version_info[0] < 3:
     from ConfigParser import NoOptionError, ConfigParser
 else:
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 '.'")