[1.6.x] Updated six to 1.9.0.

Backport of 52f0b2b62262743d5f935ddae29428e661b5d8ea from master

1 files changed, 84 insertions, 20 deletions

diff --git a/django/utils/six.py b/django/utils/six.py
index 521a384d83..8bd322ebdc 100644
--- a/django/utils/six.py
+++ b/django/utils/six.py
@@ -1,6 +1,6 @@
 """Utilities for writing code that runs on Python 2 and 3"""
 
-# Copyright (c) 2010-2014 Benjamin Peterson
+# Copyright (c) 2010-2015 Benjamin Peterson
 #
 # Permission is hereby granted, free of charge, to any person obtaining a copy
 # of this software and associated documentation files (the "Software"), to deal
@@ -23,12 +23,13 @@
 from __future__ import absolute_import
 
 import functools
+import itertools
 import operator
 import sys
 import types
 
 __author__ = "Benjamin Peterson <benjamin@python.org>"
-__version__ = "1.8.0"
+__version__ = "1.9.0"
 
 
 # Useful for very coarse version differentiation.
@@ -88,8 +89,12 @@ class _LazyDescr(object):
     def __get__(self, obj, tp):
         result = self._resolve()
         setattr(obj, self.name, result) # Invokes __set__.
-        # This is a bit ugly, but it avoids running this again.
-        delattr(obj.__class__, self.name)
+        try:
+            # This is a bit ugly, but it avoids running this again by
+            # removing this descriptor.
+            delattr(obj.__class__, self.name)
+        except AttributeError:
+            pass
         return result
 
 
@@ -554,6 +559,12 @@ if PY3:
 
     def iterlists(d, **kw):
         return iter(d.lists(**kw))
+
+    viewkeys = operator.methodcaller("keys")
+
+    viewvalues = operator.methodcaller("values")
+
+    viewitems = operator.methodcaller("items")
 else:
     def iterkeys(d, **kw):
         return iter(d.iterkeys(**kw))
@@ -567,6 +578,12 @@ else:
     def iterlists(d, **kw):
         return iter(d.iterlists(**kw))
 
+    viewkeys = operator.methodcaller("viewkeys")
+
+    viewvalues = operator.methodcaller("viewvalues")
+
+    viewitems = operator.methodcaller("viewitems")
+
 _add_doc(iterkeys, "Return an iterator over the keys of a dictionary.")
 _add_doc(itervalues, "Return an iterator over the values of a dictionary.")
 _add_doc(iteritems,
@@ -593,6 +610,9 @@ if PY3:
     import io
     StringIO = io.StringIO
     BytesIO = io.BytesIO
+    _assertCountEqual = "assertCountEqual"
+    _assertRaisesRegex = "assertRaisesRegex"
+    _assertRegex = "assertRegex"
 else:
     def b(s):
         return s
@@ -605,14 +625,28 @@ else:
         return ord(bs[0])
     def indexbytes(buf, i):
         return ord(buf[i])
-    def iterbytes(buf):
-        return (ord(byte) for byte in buf)
+    iterbytes = functools.partial(itertools.imap, ord)
     import StringIO
     StringIO = BytesIO = StringIO.StringIO
+    _assertCountEqual = "assertItemsEqual"
+    _assertRaisesRegex = "assertRaisesRegexp"
+    _assertRegex = "assertRegexpMatches"
 _add_doc(b, """Byte literal""")
 _add_doc(u, """Text literal""")
 
 
+def assertCountEqual(self, *args, **kwargs):
+    return getattr(self, _assertCountEqual)(*args, **kwargs)
+
+
+def assertRaisesRegex(self, *args, **kwargs):
+    return getattr(self, _assertRaisesRegex)(*args, **kwargs)
+
+
+def assertRegex(self, *args, **kwargs):
+    return getattr(self, _assertRegex)(*args, **kwargs)
+
+
 if PY3:
     exec_ = getattr(moves.builtins, "exec")
 
@@ -643,6 +677,21 @@ else:
 """)
 
 
+if sys.version_info[:2] == (3, 2):
+    exec_("""def raise_from(value, from_value):
+    if from_value is None:
+        raise value
+    raise value from from_value
+""")
+elif sys.version_info[:2] > (3, 2):
+    exec_("""def raise_from(value, from_value):
+    raise value from from_value
+""")
+else:
+    def raise_from(value, from_value):
+        raise value
+
+
 print_ = getattr(moves.builtins, "print", None)
 if print_ is None:
     def print_(*args, **kwargs):
@@ -697,6 +746,14 @@ if print_ is None:
                 write(sep)
             write(arg)
         write(end)
+if sys.version_info[:2] < (3, 3):
+    _print = print_
+    def print_(*args, **kwargs):
+        fp = kwargs.get("file", sys.stdout)
+        flush = kwargs.pop("flush", False)
+        _print(*args, **kwargs)
+        if flush and fp is not None:
+            fp.flush()
 
 _add_doc(reraise, """Reraise an exception.""")
 
@@ -704,7 +761,7 @@ if sys.version_info[0:2] < (3, 4):
     def wraps(wrapped, assigned=functools.WRAPPER_ASSIGNMENTS,
               updated=functools.WRAPPER_UPDATES):
         def wrapper(f):
-            f = functools.wraps(wrapped)(f)
+            f = functools.wraps(wrapped, assigned, updated)(f)
             f.__wrapped__ = wrapped
             return f
         return wrapper
@@ -737,6 +794,25 @@ def add_metaclass(metaclass):
         return metaclass(cls.__name__, cls.__bases__, orig_vars)
     return wrapper
 
+
+def python_2_unicode_compatible(klass):
+    """
+    A decorator that defines __unicode__ and __str__ methods under Python 2.
+    Under Python 3 it does nothing.
+
+    To support Python 2 and 3 with a single code base, define a __str__ method
+    returning text and apply this decorator to the class.
+    """
+    if PY2:
+        if '__str__' not in klass.__dict__:
+            raise ValueError("@python_2_unicode_compatible cannot be applied "
+                             "to %s because it doesn't define __str__()." %
+                             klass.__name__)
+        klass.__unicode__ = klass.__str__
+        klass.__str__ = lambda self: self.__unicode__().encode('utf-8')
+    return klass
+
+
 # Complete the moves implementation.
 # This code is at the end of this module to speed up module loading.
 # Turn this module into a package.
@@ -765,24 +841,12 @@ sys.meta_path.append(_importer)
 ### Additional customizations for Django ###
 
 if PY3:
-    _assertRaisesRegex = "assertRaisesRegex"
-    _assertRegex = "assertRegex"
     memoryview = memoryview
 else:
-    _assertRaisesRegex = "assertRaisesRegexp"
-    _assertRegex = "assertRegexpMatches"
-    # memoryview and buffer are not stricly equivalent, but should be fine for
+    # memoryview and buffer are not strictly equivalent, but should be fine for
     # django core usage (mainly BinaryField). However, Jython doesn't support
     # buffer (see http://bugs.jython.org/issue1521), so we have to be careful.
     if sys.platform.startswith('java'):
         memoryview = memoryview
     else:
         memoryview = buffer
-
-
-def assertRaisesRegex(self, *args, **kwargs):
-    return getattr(self, _assertRaisesRegex)(*args, **kwargs)
-
-
-def assertRegex(self, *args, **kwargs):
-    return getattr(self, _assertRegex)(*args, **kwargs)