[py3] Bundled six for Python 3 compatibility.

Refs #18363.

django/utils/py3.py

@@ -1,109 +0,0 @@
-# Compatibility layer for running Django both in 2.x and 3.x
-
-import sys
-
-if sys.version_info[0] < 3:
-    PY3 = False
-    # Changed module locations
-    from urlparse import (urlparse, urlunparse, urljoin, urlsplit, urlunsplit,
-                          urldefrag, parse_qsl)
-    from urllib import (quote, unquote, quote_plus, urlopen, urlencode,
-                        url2pathname, urlretrieve, unquote_plus)
-    from urllib2 import (Request, OpenerDirector, UnknownHandler, HTTPHandler,
-                         HTTPSHandler, HTTPDefaultErrorHandler, FTPHandler,
-                         HTTPError, HTTPErrorProcessor)
-    import urllib2
-    import Cookie as cookies
-    try:
-        import cPickle as pickle
-    except ImportError:
-        import pickle
-    try:
-        import thread
-    except ImportError:
-        import dummy_thread as thread
-    from htmlentitydefs import name2codepoint
-    import HTMLParser
-    from os import getcwdu
-    from itertools import izip as zip
-    unichr = unichr
-    xrange = xrange
-    maxsize = sys.maxint
-
-    # Type aliases
-    string_types = basestring,
-    text_type = unicode
-    integer_types = int, long
-    long_type = long
-
-    from io import BytesIO as OutputIO
-
-    # Glue code for syntax differences
-    def reraise(tp, value, tb=None):
-        exec("raise tp, value, tb")
-
-    def with_metaclass(meta, base=object):
-        class _DjangoBase(base):
-            __metaclass__ = meta
-        return _DjangoBase
-
-    iteritems = lambda o: o.iteritems()
-    itervalues = lambda o: o.itervalues()
-    iterkeys = lambda o: o.iterkeys()
-
-    # n() is useful when python3 needs a str (unicode), and python2 str (bytes)
-    n = lambda s: s.encode('utf-8')
-
-else:
-    PY3 = True
-    import builtins
-
-    # Changed module locations
-    from urllib.parse import (urlparse, urlunparse, urlencode, urljoin,
-                              urlsplit, urlunsplit, quote, unquote,
-                              quote_plus, unquote_plus, parse_qsl,
-                              urldefrag)
-    from urllib.request import (urlopen, url2pathname, Request, OpenerDirector,
-                                UnknownHandler, HTTPHandler, HTTPSHandler,
-                                HTTPDefaultErrorHandler, FTPHandler,
-                                HTTPError, HTTPErrorProcessor, urlretrieve)
-    import urllib.request as urllib2
-    import http.cookies as cookies
-    import pickle
-    try:
-        import _thread as thread
-    except ImportError:
-        import _dummy_thread as thread
-    from html.entities import name2codepoint
-    import html.parser as HTMLParser
-    from os import getcwd as getcwdu
-    zip = zip
-    unichr = chr
-    xrange = range
-    maxsize = sys.maxsize
-
-    # Type aliases
-    string_types = str,
-    text_type = str
-    integer_types = int,
-    long_type = int
-
-    from io import StringIO as OutputIO
-
-    # Glue code for syntax differences
-    def reraise(tp, value, tb=None):
-        if value.__traceback__ is not tb:
-            raise value.with_traceback(tb)
-        raise value
-
-    def with_metaclass(meta, base=object):
-        ns = dict(base=base, meta=meta)
-        exec("""class _DjangoBase(base, metaclass=meta):
-    pass""", ns)
-        return ns["_DjangoBase"]
-
-    iteritems = lambda o: o.items()
-    itervalues = lambda o: o.values()
-    iterkeys = lambda o: o.keys()
-
-    n = lambda s: s

django/utils/six.py

@@ -0,0 +1,353 @@
+"""Utilities for writing code that runs on Python 2 and 3"""
+
+import operator
+import sys
+import types
+
+__author__ = "Benjamin Peterson <benjamin@python.org>"
+__version__ = "1.1.0"
+
+
+# True if we are running on Python 3.
+PY3 = sys.version_info[0] == 3
+
+if PY3:
+    string_types = str,
+    integer_types = int,
+    class_types = type,
+    text_type = str
+    binary_type = bytes
+
+    MAXSIZE = sys.maxsize
+else:
+    string_types = basestring,
+    integer_types = (int, long)
+    class_types = (type, types.ClassType)
+    text_type = unicode
+    binary_type = str
+
+    # It's possible to have sizeof(long) != sizeof(Py_ssize_t).
+    class X(object):
+        def __len__(self):
+            return 1 << 31
+    try:
+        len(X())
+    except OverflowError:
+        # 32-bit
+        MAXSIZE = int((1 << 31) - 1)
+    else:
+        # 64-bit
+        MAXSIZE = int((1 << 63) - 1)
+    del X
+
+
+def _add_doc(func, doc):
+    """Add documentation to a function."""
+    func.__doc__ = doc
+
+
+def _import_module(name):
+    """Import module, returning the module after the last dot."""
+    __import__(name)
+    return sys.modules[name]
+
+
+class _LazyDescr(object):
+
+    def __init__(self, name):
+        self.name = name
+
+    def __get__(self, obj, tp):
+        result = self._resolve()
+        setattr(obj, self.name, result)
+        # This is a bit ugly, but it avoids running this again.
+        delattr(tp, self.name)
+        return result
+
+
+class MovedModule(_LazyDescr):
+
+    def __init__(self, name, old, new=None):
+        super(MovedModule, self).__init__(name)
+        if PY3:
+            if new is None:
+                new = name
+            self.mod = new
+        else:
+            self.mod = old
+
+    def _resolve(self):
+        return _import_module(self.mod)
+
+
+class MovedAttribute(_LazyDescr):
+
+    def __init__(self, name, old_mod, new_mod, old_attr=None, new_attr=None):
+        super(MovedAttribute, self).__init__(name)
+        if PY3:
+            if new_mod is None:
+                new_mod = name
+            self.mod = new_mod
+            if new_attr is None:
+                if old_attr is None:
+                    new_attr = name
+                else:
+                    new_attr = old_attr
+            self.attr = new_attr
+        else:
+            self.mod = old_mod
+            if old_attr is None:
+                old_attr = name
+            self.attr = old_attr
+
+    def _resolve(self):
+        module = _import_module(self.mod)
+        return getattr(module, self.attr)
+
+
+
+class _MovedItems(types.ModuleType):
+    """Lazy loading of moved objects"""
+
+
+_moved_attributes = [
+    MovedAttribute("cStringIO", "cStringIO", "io", "StringIO"),
+    MovedAttribute("filter", "itertools", "builtins", "ifilter", "filter"),
+    MovedAttribute("map", "itertools", "builtins", "imap", "map"),
+    MovedAttribute("reload_module", "__builtin__", "imp", "reload"),
+    MovedAttribute("reduce", "__builtin__", "functools"),
+    MovedAttribute("StringIO", "StringIO", "io"),
+    MovedAttribute("xrange", "__builtin__", "builtins", "xrange", "range"),
+    MovedAttribute("zip", "itertools", "builtins", "izip", "zip"),
+
+    MovedModule("builtins", "__builtin__"),
+    MovedModule("configparser", "ConfigParser"),
+    MovedModule("copyreg", "copy_reg"),
+    MovedModule("http_cookiejar", "cookielib", "http.cookiejar"),
+    MovedModule("http_cookies", "Cookie", "http.cookies"),
+    MovedModule("html_entities", "htmlentitydefs", "html.entities"),
+    MovedModule("html_parser", "HTMLParser", "html.parser"),
+    MovedModule("http_client", "httplib", "http.client"),
+    MovedModule("BaseHTTPServer", "BaseHTTPServer", "http.server"),
+    MovedModule("CGIHTTPServer", "CGIHTTPServer", "http.server"),
+    MovedModule("SimpleHTTPServer", "SimpleHTTPServer", "http.server"),
+    MovedModule("cPickle", "cPickle", "pickle"),
+    MovedModule("queue", "Queue"),
+    MovedModule("reprlib", "repr"),
+    MovedModule("socketserver", "SocketServer"),
+    MovedModule("tkinter", "Tkinter"),
+    MovedModule("tkinter_dialog", "Dialog", "tkinter.dialog"),
+    MovedModule("tkinter_filedialog", "FileDialog", "tkinter.filedialog"),
+    MovedModule("tkinter_scrolledtext", "ScrolledText", "tkinter.scrolledtext"),
+    MovedModule("tkinter_simpledialog", "SimpleDialog", "tkinter.simpledialog"),
+    MovedModule("tkinter_tix", "Tix", "tkinter.tix"),
+    MovedModule("tkinter_constants", "Tkconstants", "tkinter.constants"),
+    MovedModule("tkinter_dnd", "Tkdnd", "tkinter.dnd"),
+    MovedModule("tkinter_colorchooser", "tkColorChooser",
+                "tkinter.colorchooser"),
+    MovedModule("tkinter_commondialog", "tkCommonDialog",
+                "tkinter.commondialog"),
+    MovedModule("tkinter_tkfiledialog", "tkFileDialog", "tkinter.filedialog"),
+    MovedModule("tkinter_font", "tkFont", "tkinter.font"),
+    MovedModule("tkinter_messagebox", "tkMessageBox", "tkinter.messagebox"),
+    MovedModule("tkinter_tksimpledialog", "tkSimpleDialog",
+                "tkinter.simpledialog"),
+    MovedModule("urllib_robotparser", "robotparser", "urllib.robotparser"),
+    MovedModule("winreg", "_winreg"),
+]
+for attr in _moved_attributes:
+    setattr(_MovedItems, attr.name, attr)
+del attr
+
+moves = sys.modules["six.moves"] = _MovedItems("moves")
+
+
+def add_move(move):
+    """Add an item to six.moves."""
+    setattr(_MovedItems, move.name, move)
+
+
+def remove_move(name):
+    """Remove item from six.moves."""
+    try:
+        delattr(_MovedItems, name)
+    except AttributeError:
+        try:
+            del moves.__dict__[name]
+        except KeyError:
+            raise AttributeError("no such move, %r" % (name,))
+
+
+if PY3:
+    _meth_func = "__func__"
+    _meth_self = "__self__"
+
+    _func_code = "__code__"
+    _func_defaults = "__defaults__"
+
+    _iterkeys = "keys"
+    _itervalues = "values"
+    _iteritems = "items"
+else:
+    _meth_func = "im_func"
+    _meth_self = "im_self"
+
+    _func_code = "func_code"
+    _func_defaults = "func_defaults"
+
+    _iterkeys = "iterkeys"
+    _itervalues = "itervalues"
+    _iteritems = "iteritems"
+
+
+if PY3:
+    def get_unbound_function(unbound):
+        return unbound
+
+
+    advance_iterator = next
+
+    def callable(obj):
+        return any("__call__" in klass.__dict__ for klass in type(obj).__mro__)
+else:
+    def get_unbound_function(unbound):
+        return unbound.im_func
+
+
+    def advance_iterator(it):
+        return it.next()
+
+    callable = callable
+_add_doc(get_unbound_function,
+         """Get the function out of a possibly unbound function""")
+
+
+get_method_function = operator.attrgetter(_meth_func)
+get_method_self = operator.attrgetter(_meth_self)
+get_function_code = operator.attrgetter(_func_code)
+get_function_defaults = operator.attrgetter(_func_defaults)
+
+
+def iterkeys(d):
+    """Return an iterator over the keys of a dictionary."""
+    return getattr(d, _iterkeys)()
+
+def itervalues(d):
+    """Return an iterator over the values of a dictionary."""
+    return getattr(d, _itervalues)()
+
+def iteritems(d):
+    """Return an iterator over the (key, value) pairs of a dictionary."""
+    return getattr(d, _iteritems)()
+
+
+if PY3:
+    def b(s):
+        return s.encode("latin-1")
+    def u(s):
+        return s
+    if sys.version_info[1] <= 1:
+        def int2byte(i):
+            return bytes((i,))
+    else:
+        # This is about 2x faster than the implementation above on 3.2+
+        int2byte = operator.methodcaller("to_bytes", 1, "big")
+    import io
+    StringIO = io.StringIO
+    BytesIO = io.BytesIO
+else:
+    def b(s):
+        return s
+    def u(s):
+        return unicode(s, "unicode_escape")
+    int2byte = chr
+    import StringIO
+    StringIO = BytesIO = StringIO.StringIO
+_add_doc(b, """Byte literal""")
+_add_doc(u, """Text literal""")
+
+
+if PY3:
+    import builtins
+    exec_ = getattr(builtins, "exec")
+
+
+    def reraise(tp, value, tb=None):
+        if value.__traceback__ is not tb:
+            raise value.with_traceback(tb)
+        raise value
+
+
+    print_ = getattr(builtins, "print")
+    del builtins
+
+else:
+    def exec_(code, globs=None, locs=None):
+        """Execute code in a namespace."""
+        if globs is None:
+            frame = sys._getframe(1)
+            globs = frame.f_globals
+            if locs is None:
+                locs = frame.f_locals
+            del frame
+        elif locs is None:
+            locs = globs
+        exec("""exec code in globs, locs""")
+
+
+    exec_("""def reraise(tp, value, tb=None):
+    raise tp, value, tb
+""")
+
+
+    def print_(*args, **kwargs):
+        """The new-style print function."""
+        fp = kwargs.pop("file", sys.stdout)
+        if fp is None:
+            return
+        def write(data):
+            if not isinstance(data, basestring):
+                data = str(data)
+            fp.write(data)
+        want_unicode = False
+        sep = kwargs.pop("sep", None)
+        if sep is not None:
+            if isinstance(sep, unicode):
+                want_unicode = True
+            elif not isinstance(sep, str):
+                raise TypeError("sep must be None or a string")
+        end = kwargs.pop("end", None)
+        if end is not None:
+            if isinstance(end, unicode):
+                want_unicode = True
+            elif not isinstance(end, str):
+                raise TypeError("end must be None or a string")
+        if kwargs:
+            raise TypeError("invalid keyword arguments to print()")
+        if not want_unicode:
+            for arg in args:
+                if isinstance(arg, unicode):
+                    want_unicode = True
+                    break
+        if want_unicode:
+            newline = unicode("\n")
+            space = unicode(" ")
+        else:
+            newline = "\n"
+            space = " "
+        if sep is None:
+            sep = space
+        if end is None:
+            end = newline
+        for i, arg in enumerate(args):
+            if i:
+                write(sep)
+            write(arg)
+        write(end)
+
+_add_doc(reraise, """Reraise an exception.""")
+
+
+def with_metaclass(meta, base=object):
+    """Create a base class with a metaclass."""
+    return meta("NewBase", (base,), {})

docs/topics/python3.txt

@@ -2,251 +2,48 @@
 Python 3 compatibility
 ======================
 
-Django 1.5 introduces a compatibility layer that allows the code to be run both
+Django 1.5 is the first version of Django to support Python 3.
-in Python 2 (2.6/2.7) and Python 3 (>= 3.2) (*work in progress*).
 
-This document is not meant as a complete Python 2 to Python 3 migration guide.
+The same code runs both on Python 2 (≥2.6.5) and Python 3 (≥3.2). To
-There are many existing resources you can read. But we describe some utilities
+achieve this:
-and guidelines that we recommend you should use when you want to ensure your
-code can be run with both Python 2 and 3.
 
-* http://docs.python.org/py3k/howto/pyporting.html
+- wherever possible, Django uses the six_ compatibility layer,
-* http://python3porting.com/
+- all modules declare ``from __future__ import unicode_literals``.
 
-django.utils.py3
+.. _six: http://packages.python.org/six/
+
+This document is not meant as a Python 2 to Python 3 migration guide. There
+are many existing resources, including `Python's official porting guide`_. But
+it describes guidelines that apply to Django's code and are recommended for
+pluggable apps that run with both Python 2 and 3.
+
+.. _Python's official porting guide: http://docs.python.org/py3k/howto/pyporting.html
+
+.. module: django.utils.six
+
+django.utils.six
 ================
 
-Whenever a symbol or module has different semantics or different locations on
+Read the documentation of six_. It's the canonical compatibility library for
-Python 2 and Python 3, you can import it from ``django.utils.py3`` where it
+supporting Python 2 and 3 in a single codebase.
-will be automatically converted depending on your current Python version.
 
-PY3
+``six`` is bundled with Django: you can import it as :mod:`django.utils.six`.
----
 
-If you need to know anywhere in your code if you are running Python 3 or a
+.. _string-handling:
-previous Python 2 version, you can check the ``PY3`` boolean variable::
-
-    from django.utils.py3 import PY3
-
-    if PY3:
-        # Do stuff Python 3-wise
-    else:
-        # Do stuff Python 2-wise
-
-This should be considered as a last resort solution when it is not possible
-to import a compatible name from django.utils.py3, as described in the sections
-below.
 
 String handling
 ===============
 
-In Python 3, all strings are considered Unicode strings by default. Byte strings
+In Python 3, all strings are considered Unicode strings by default. Byte
-have to be prefixed with the letter 'b'. To mimic the same behaviour in Python 2,
+strings must be prefixed with the letter ``b``. In order to enable the same
-we recommend you import ``unicode_literals`` from the ``__future__`` library::
+behavior in Python 2, every module must import ``unicode_literals`` from
+``__future__``::
 
     from __future__ import unicode_literals
 
     my_string = "This is an unicode literal"
     my_bytestring = b"This is a bytestring"
 
-Be cautious if you have to slice bytestrings.
+Be cautious if you have to `slice bytestrings`_.
-See http://docs.python.org/py3k/howto/pyporting.html#bytes-literals
-
-Different expected strings
---------------------------
-
-Some method parameters have changed the expected string type of a parameter.
-For example, ``strftime`` format parameter expects a bytestring on Python 2 but
-a normal (Unicode) string on Python 3. For these cases, ``django.utils.py3``
-provides a ``n()`` function which encodes the string parameter only with
-Python 2.
-
-    >>> from __future__ import unicode_literals
-    >>> from datetime import datetime
-
-    >>> print(datetime.date(2012, 5, 21).strftime(n("%m → %Y")))
-    05 → 2012
-
-Renamed types
-=============
-
-Several types are named differently in Python 2 and Python 3. In order to keep
-compatibility while using those types, import their corresponding aliases from
-``django.utils.py3``.
-
-===========  =========  =====================
-Python 2     Python 3   django.utils.py3
-===========  =========  =====================
-basestring,  str,       string_types (tuple)
-unicode      str        text_type
-int, long    int,       integer_types (tuple)
-long         int        long_type
-===========  =========  =====================
-
-String aliases
---------------
-
-Code sample::
-
-    if isinstance(foo, basestring):
-        print("foo is a string")
-
-    # I want to convert a number to a Unicode string
-    bar = 45
-    bar_string = unicode(bar)
-
-Should be replaced by::
-
-    from django.utils.py3 import string_types, text_type
-
-    if isinstance(foo, string_types):
-        print("foo is a string")
-
-    # I want to convert a number to a Unicode string
-    bar = 45
-    bar_string = text_type(bar)
-
-No more long type
------------------
-
-``long`` and ``int`` types have been unified in Python 3, meaning that  ``long``
-is no longer available. ``django.utils.py3`` provides both ``long_type`` and
-``integer_types`` aliases. For example:
-
-.. code-block:: python
-
-    # Old Python 2 code
-    my_var = long(333463247234623)
-    if isinstance(my_var, (int, long)):
-        # ...
-
-Should be replaced by:
-
-.. code-block:: python
-
-    from django.utils.py3 import long_type, integer_types
-
-    my_var = long_type(333463247234623)
-    if isinstance(my_var, integer_types):
-        # ...
-
-
-Changed module locations
-========================
-
-The following modules have changed their location in Python 3. Therefore, it is
-recommended to import them from the ``django.utils.py3`` compatibility layer:
-
-=============================== ======================================  ======================
-Python 2                        Python3                                 django.utils.py3
-=============================== ======================================  ======================
-Cookie                          http.cookies                            cookies
-
-urlparse.urlparse               urllib.parse.urlparse                   urlparse
-urlparse.urlunparse             urllib.parse.urlunparse                 urlunparse
-urlparse.urljoin                urllib.parse.urljoin                    urljoin
-urlparse.urlsplit               urllib.parse.urlsplit                   urlsplit
-urlparse.urlunsplit             urllib.parse.urlunsplit                 urlunsplit
-urlparse.urldefrag              urllib.parse.urldefrag                  urldefrag
-urlparse.parse_qsl              urllib.parse.parse_qsl                  parse_qsl
-urllib.quote                    urllib.parse.quote                      quote
-urllib.unquote                  urllib.parse.unquote                    unquote
-urllib.quote_plus               urllib.parse.quote_plus                 quote_plus
-urllib.unquote_plus             urllib.parse.unquote_plus               unquote_plus
-urllib.urlencode                urllib.parse.urlencode                  urlencode
-urllib.urlopen                  urllib.request.urlopen                  urlopen
-urllib.url2pathname             urllib.request.url2pathname             url2pathname
-urllib.urlretrieve              urllib.request.urlretrieve              urlretrieve
-urllib2                         urllib.request                          urllib2
-urllib2.Request                 urllib.request.Request                  Request
-urllib2.OpenerDirector          urllib.request.OpenerDirector           OpenerDirector
-urllib2.UnknownHandler          urllib.request.UnknownHandler           UnknownHandler
-urllib2.HTTPHandler             urllib.request.HTTPHandler              HTTPHandler
-urllib2.HTTPSHandler            urllib.request.HTTPSHandler             HTTPSHandler
-urllib2.HTTPDefaultErrorHandler urllib.request.HTTPDefaultErrorHandler  HTTPDefaultErrorHandler
-urllib2.FTPHandler              urllib.request.FTPHandler               FTPHandler
-urllib2.HTTPError               urllib.request.HTTPError                HTTPError
-urllib2.HTTPErrorProcessor      urllib.request.HTTPErrorProcessor       HTTPErrorProcessor
-
-htmlentitydefs.name2codepoint   html.entities.name2codepoint            name2codepoint
-HTMLParser                      html.parser                             HTMLParser
-cPickle/pickle                  pickle                                  pickle
-thread/dummy_thread             _thread/_dummy_thread                   thread
-
-os.getcwdu                      os.getcwd                               getcwdu
-itertools.izip                  zip                                     zip
-sys.maxint                      sys.maxsize                             maxsize
-unichr                          chr                                     unichr
-xrange                          range                                   xrange
-=============================== ======================================  ======================
-
-
-Output encoding now Unicode
-===========================
-
-If you want to catch stdout/stderr output, the output content is UTF-8 encoded
-in Python 2, while it is Unicode strings in Python 3. You can use the OutputIO
-stream to capture this output::
-
-    from django.utils.py3 import OutputIO
-
-    try:
-        old_stdout = sys.stdout
-        out = OutputIO()
-        sys.stdout = out
-        # Do stuff which produces standard output
-        result = out.getvalue()
-    finally:
-        sys.stdout = old_stdout
-
-Dict iteritems/itervalues/iterkeys
-==================================
-
-The iteritems(), itervalues() and iterkeys() methods of dictionaries do not
-exist any more in Python 3, simply because they represent the default items()
-values() and keys() behavior in Python 3. Therefore, to keep compatibility,
-use similar functions from ``django.utils.py3``::
-
-    from django.utils.py3 import iteritems, itervalues, iterkeys
-
-    my_dict = {'a': 21, 'b': 42}
-    for key, value in iteritems(my_dict):
-        # ...
-    for value in itervalues(my_dict):
-        # ...
-    for key in iterkeys(my_dict):
-        # ...
-
-Note that in Python 3, dict.keys(), dict.items() and dict.values() return
-"views" instead of lists. Wrap them into list() if you really need their return
-values to be in a list.
-
-http://docs.python.org/release/3.0.1/whatsnew/3.0.html#views-and-iterators-instead-of-lists
-
-Metaclass
-=========
-
-The syntax for declaring metaclasses has changed in Python 3.
-``django.utils.py3`` offers a compatible way to declare metaclasses::
-
-    from django.utils.py3 import with_metaclass
-
-    class MyClass(with_metaclass(SubClass1, SubClass2,...)):
-        # ...
-
-Re-raising exceptions
-=====================
-
-One of the syntaxes to raise exceptions (raise E, V, T) is gone in Python 3.
-This is especially used in very specific cases where you want to re-raise a
-different exception that the initial one, while keeping the original traceback.
-So, instead of::
-
-    raise Exception, Exception(msg), traceback
-
-Use::
-
-    from django.utils.py3 import reraise
-
-    reraise(Exception, Exception(msg), traceback)
 
+.. _slice bytestrings: http://docs.python.org/py3k/howto/pyporting.html#bytes-literals