Merged revisions 58742-58816 via svnmerge from

gvanrossum · gvanrossum · commit 2cc30daa863d · 2007-11-02T23:46:40.000Z
svn+ssh://pythondev@svn.python.org/python/trunk ........ r58745 | georg.brandl | 2007-11-01 10:19:33 -0700 (Thu, 01 Nov 2007) | 2 lines #1364: os.lstat is available on Windows too, as an alias to os.stat. ........ r58750 | christian.heimes | 2007-11-01 12:48:10 -0700 (Thu, 01 Nov 2007) | 1 line Backport of import tests for bug http://bugs.python.org/issue1293 and bug http://bugs.python.org/issue1342 ........ r58751 | christian.heimes | 2007-11-01 13:11:06 -0700 (Thu, 01 Nov 2007) | 1 line Removed non ASCII text from test as requested by Guido. Sorry :/ ........ r58753 | georg.brandl | 2007-11-01 13:37:02 -0700 (Thu, 01 Nov 2007) | 2 lines Fix markup glitch. ........ r58757 | gregory.p.smith | 2007-11-01 14:08:14 -0700 (Thu, 01 Nov 2007) | 4 lines Fix bug introduced in revision 58385. Database keys could no longer have NULL bytes in them. Replace the errant strdup with a malloc+memcpy. Adds a unit test for the correct behavior. ........ r58758 | gregory.p.smith | 2007-11-01 14:15:36 -0700 (Thu, 01 Nov 2007) | 3 lines Undo revision 58533 58534 fixes. Those were a workaround for a problem introduced by 58385. ........ r58759 | gregory.p.smith | 2007-11-01 14:17:47 -0700 (Thu, 01 Nov 2007) | 2 lines false "fix" undone as correct problem was found and fixed. ........ r58765 | mark.summerfield | 2007-11-02 01:24:59 -0700 (Fri, 02 Nov 2007) | 3 lines Added more file-handling related cross-references. ........ r58766 | nick.coghlan | 2007-11-02 03:09:12 -0700 (Fri, 02 Nov 2007) | 1 line Fix for bug 1705170 - contextmanager swallowing StopIteration (2.5 backport candidate) ........ r58784 | thomas.heller | 2007-11-02 12:10:24 -0700 (Fri, 02 Nov 2007) | 4 lines Issue #1292: On alpha, arm, ppc, and s390 linux systems the --with-system-ffi configure option defaults to "yes" because the bundled libffi sources are too old. ........ r58785 | thomas.heller | 2007-11-02 12:11:23 -0700 (Fri, 02 Nov 2007) | 1 line Enable the full ctypes c_longdouble tests again. ........ r58796 | georg.brandl | 2007-11-02 13:06:17 -0700 (Fri, 02 Nov 2007) | 4 lines Make "hashable" a glossary entry and clarify docs on __cmp__, __eq__ and __hash__. I hope the concept of hashability is better understandable now. Thanks to Tim Hatch for pointing out the flaws here. ........
diff --git a/Doc/c-api/concrete.rst b/Doc/c-api/concrete.rst
@@ -2223,8 +2223,8 @@ Dictionary Objects
 .. cfunction:: int PyDict_SetItem(PyObject *p, PyObject *key, PyObject *val)
 
    Insert *value* into the dictionary *p* with a key of *key*.  *key* must be
-   hashable; if it isn't, :exc:`TypeError` will be raised. Return ``0`` on success
-   or ``-1`` on failure.
+   :term:`hashable`; if it isn't, :exc:`TypeError` will be raised. Return ``0``
+   on success or ``-1`` on failure.
 
 
 .. cfunction:: int PyDict_SetItemString(PyObject *p, const char *key, PyObject *val)
diff --git a/Doc/glossary.rst b/Doc/glossary.rst
@@ -140,6 +140,20 @@ Glossary
       in the past to create a "free-threaded" interpreter (one which locks
       shared data at a much finer granularity), but performance suffered in the
       common single-processor case.
+
+   hashable
+      An object is *hashable* if it has a hash value that never changes during
+      its lifetime (it needs a :meth:`__hash__` method), and can be compared to
+      other objects (it needs an :meth:`__eq__` or :meth:`__cmp__` method).
+      Hashable objects that compare equal must have the same hash value.
+
+      Hashability makes an object usable as a dictionary key and a set member,
+      because these data structures use the hash value internally.
+
+      All of Python's immutable built-in objects are hashable, while all mutable
+      containers (such as lists or dictionaries) are not.  Objects that are
+      instances of user-defined classes are hashable by default; they all
+      compare unequal, and their hash value is their :func:`id`.
     
    IDLE
       An Integrated Development Environment for Python.  IDLE is a basic editor
diff --git a/Doc/library/datetime.rst b/Doc/library/datetime.rst
@@ -260,7 +260,7 @@ compared to an object of a different type, :exc:`TypeError` is raised unless the
 comparison is ``==`` or ``!=``.  The latter cases return :const:`False` or
 :const:`True`, respectively.
 
-:class:`timedelta` objects are hashable (usable as dictionary keys), support
+:class:`timedelta` objects are :term:`hashable` (usable as dictionary keys), support
 efficient pickling, and in Boolean contexts, a :class:`timedelta` object is
 considered to be true if and only if it isn't equal to ``timedelta(0)``.
 
diff --git a/Doc/library/difflib.rst b/Doc/library/difflib.rst
@@ -18,7 +18,7 @@ diffs. For comparing directories and files, see also, the :mod:`filecmp` module.
 .. class:: SequenceMatcher
 
    This is a flexible class for comparing pairs of sequences of any type, so long
-   as the sequence elements are hashable.  The basic algorithm predates, and is a
+   as the sequence elements are :term:`hashable`.  The basic algorithm predates, and is a
    little fancier than, an algorithm published in the late 1980's by Ratcliff and
    Obershelp under the hyperbolic name "gestalt pattern matching."  The idea is to
    find the longest contiguous matching subsequence that contains no "junk"
@@ -305,7 +305,7 @@ The :class:`SequenceMatcher` class has this constructor:
    on blanks or hard tabs.
 
    The optional arguments *a* and *b* are sequences to be compared; both default to
-   empty strings.  The elements of both sequences must be hashable.
+   empty strings.  The elements of both sequences must be :term:`hashable`.
 
 :class:`SequenceMatcher` objects have the following methods:
 
diff --git a/Doc/library/functions.rst b/Doc/library/functions.rst
@@ -747,9 +747,9 @@ available.  They are listed here in alphabetical order.
    value of ``None`` (if no newlines have been seen yet), ``'\n'``,
    ``'\r'``, ``'\r\n'``, or a tuple containing all the newline types seen.
 
-   See also the :mod:`fileinput` module, the file-related functions in the
-   :mod:`os` module, and the :mod:`os.path` module.
-
+   Python provides many file handling modules including
+   :mod:`fileinput`, :mod:`os`, :mod:`os.path`, :mod:`tempfile`, and
+   :mod:`shutil`.
 
 .. function:: ord(c)
 
diff --git a/Doc/library/os.rst b/Doc/library/os.rst
@@ -11,7 +11,9 @@ functionality than importing a operating system dependent built-in module like
 :mod:`posix` or :mod:`nt`. If you just want to read or write a file see
 :func:`open`, if you want to manipulate paths, see the :mod:`os.path`
 module, and if you want to read all the lines in all the files on the
-command line see the :mod:`fileinput` module.
+command line see the :mod:`fileinput` module. For creating temporary
+files and directories see the :mod:`tempfile` module, and for high-level
+file and directory handling see the :mod:`shutil` module.
 
 This module searches for an operating system dependent built-in module like
 :mod:`mac` or :mod:`posix` and exports the same functions and data as found
@@ -800,8 +802,9 @@ Files and Directories
 
 .. function:: lstat(path)
 
-   Like :func:`stat`, but do not follow symbolic links. Availability: Macintosh,
-   Unix.
+   Like :func:`stat`, but do not follow symbolic links.  This is an alias for
+   :func:`stat` on platforms that do not support symbolic links, such as
+   Windows.
 
 
 .. function:: mkfifo(path[, mode])
@@ -852,6 +855,9 @@ Files and Directories
    ``0777`` (octal).  On some systems, *mode* is ignored.  Where it is used, the
    current umask value is first masked out. Availability: Macintosh, Unix, Windows.
 
+   It is also possible to create temporary directories; see the
+   :mod:`tempfile` module's :func:`tempfile.mkdtemp` function.
+
 
 .. function:: makedirs(path[, mode])
 
diff --git a/Doc/library/random.rst b/Doc/library/random.rst
@@ -54,7 +54,7 @@ Bookkeeping functions:
 .. function:: seed([x])
 
    Initialize the basic random number generator. Optional argument *x* can be any
-   hashable object. If *x* is omitted or ``None``, current system time is used;
+   :term:`hashable` object. If *x* is omitted or ``None``, current system time is used;
    current system time is also used to initialize the generator when the module is
    first imported.  If randomness sources are provided by the operating system,
    they are used instead of the system time (see the :func:`os.urandom` function
@@ -140,7 +140,7 @@ Functions for sequences:
    (the sample) to be partitioned into grand prize and second place winners (the
    subslices).
 
-   Members of the population need not be hashable or unique.  If the population
+   Members of the population need not be :term:`hashable` or unique.  If the population
    contains repeats, then each occurrence is a possible selection in the sample.
 
    To choose a sample from a range of integers, use an :func:`range` object as an
diff --git a/Doc/library/shutil.rst b/Doc/library/shutil.rst
@@ -15,7 +15,8 @@
 
 The :mod:`shutil` module offers a number of high-level operations on files and
 collections of files.  In particular, functions are provided  which support file
-copying and removal.
+copying and removal. For operations on individual files, see also the
+:mod:`os` module.
 
 .. warning::
    
diff --git a/Doc/library/stdtypes.rst b/Doc/library/stdtypes.rst
@@ -874,7 +874,7 @@ functions based on regular expressions.
    specified, then there is no limit on the number of splits (all possible
    splits are made).
 
-   If *sep is given, consecutive delimiters are not grouped together and are
+   If *sep* is given, consecutive delimiters are not grouped together and are
    deemed to delimit empty strings (for example, ``'1,,2'.split(',')`` returns
    ``['1', '', '2']``).  The *sep* argument may consist of multiple characters
    (for example, ``'1<>2<>3'.split('<>')`` returns ``['1', '2', '3']``).
@@ -1371,7 +1371,7 @@ Set Types --- :class:`set`, :class:`frozenset`
 
 .. index:: object: set
 
-A :dfn:`set` object is an unordered collection of distinct hashable objects.
+A :dfn:`set` object is an unordered collection of distinct :term:`hashable` objects.
 Common uses include membership testing, removing duplicates from a sequence, and
 computing mathematical operations such as intersection, union, difference, and
 symmetric difference.
@@ -1387,7 +1387,7 @@ There are currently two builtin set types, :class:`set` and :class:`frozenset`.
 The :class:`set` type is mutable --- the contents can be changed using methods
 like :meth:`add` and :meth:`remove`.  Since it is mutable, it has no hash value
 and cannot be used as either a dictionary key or as an element of another set.
-The :class:`frozenset` type is immutable and hashable --- its contents cannot be
+The :class:`frozenset` type is immutable and :term:`hashable` --- its contents cannot be
 altered after it is created; it can therefore be used as a dictionary key or as
 an element of another set.
 
@@ -1487,8 +1487,7 @@ or ``a>b``. Accordingly, sets do not implement the :meth:`__cmp__` method.
 Since sets only define partial ordering (subset relationships), the output of
 the :meth:`list.sort` method is undefined for lists of sets.
 
-Set elements are like dictionary keys; they need to define both :meth:`__hash__`
-and :meth:`__eq__` methods.
+Set elements, like dictionary keys, must be :term:`hashable`.
 
 Binary operations that mix :class:`set` instances with :class:`frozenset` return
 the type of the first operand.  For example: ``frozenset('ab') | set('bc')``
@@ -1559,20 +1558,20 @@ Mapping Types --- :class:`dict`
    statement: del
    builtin: len
 
-A :dfn:`mapping` object maps immutable values to arbitrary objects.  Mappings
-are mutable objects.  There is currently only one standard mapping type, the
-:dfn:`dictionary`.
-(For other containers see the built in :class:`list`,
-:class:`set`, and :class:`tuple` classes, and the :mod:`collections`
-module.)
-
-A dictionary's keys are *almost* arbitrary values.  Only values containing
-lists, dictionaries or other mutable types (that are compared by value rather
-than by object identity) may not be used as keys.  Numeric types used for keys
-obey the normal rules for numeric comparison: if two numbers compare equal (such
-as ``1`` and ``1.0``) then they can be used interchangeably to index the same
-dictionary entry. (Note however, that since computers store floating-point
-numbers as approximations it is usually unwise to use them as dictionary keys.)
+A :dfn:`mapping` object maps :term:`hashable` values to arbitrary objects.
+Mappings are mutable objects.  There is currently only one standard mapping
+type, the :dfn:`dictionary`.  (For other containers see the built in
+:class:`list`, :class:`set`, and :class:`tuple` classes, and the
+:mod:`collections` module.)
+
+A dictionary's keys are *almost* arbitrary values.  Values that are not
+:term:`hashable`, that is, values containing lists, dictionaries or other
+mutable types (that are compared by value rather than by object identity) may
+not be used as keys.  Numeric types used for keys obey the normal rules for
+numeric comparison: if two numbers compare equal (such as ``1`` and ``1.0``)
+then they can be used interchangeably to index the same dictionary entry.  (Note
+however, that since computers store floating-point numbers as approximations it
+is usually unwise to use them as dictionary keys.)
 
 Dictionaries can be created by placing a comma-separated list of ``key: value``
 pairs within braces, for example: ``{'jack': 4098, 'sjoerd': 4127}`` or ``{4098:
@@ -1821,7 +1820,10 @@ created with the built-in :func:`file` and (more usually) :func:`open`
 constructors described in the :ref:`built-in-funcs` section. [#]_ File
 objects are also returned by some other built-in functions and methods,
 such as :func:`os.popen` and :func:`os.fdopen` and the :meth:`makefile`
-method of socket objects.
+method of socket objects. Temporary files can be created using the
+:mod:`tempfile` module, and high-level file operations such as copying,
+moving, and deleting files and directories can be achieved with the
+:mod:`shutil` module.
 
 When a file operation fails for an I/O-related reason, the exception
 :exc:`IOError` is raised.  This includes situations where the operation is not
diff --git a/Doc/library/weakref.rst b/Doc/library/weakref.rst
@@ -85,7 +85,7 @@ Extension types can easily be made to support weak references; see
    but cannot be propagated; they are handled in exactly the same way as exceptions
    raised from an object's :meth:`__del__` method.
 
-   Weak references are hashable if the *object* is hashable.  They will maintain
+   Weak references are :term:`hashable` if the *object* is hashable.  They will maintain
    their hash value even after the *object* was deleted.  If :func:`hash` is called
    the first time only after the *object* was deleted, the call will raise
    :exc:`TypeError`.
@@ -104,7 +104,7 @@ Extension types can easily be made to support weak references; see
    the proxy in most contexts instead of requiring the explicit dereferencing used
    with weak reference objects.  The returned object will have a type of either
    ``ProxyType`` or ``CallableProxyType``, depending on whether *object* is
-   callable.  Proxy objects are not hashable regardless of the referent; this
+   callable.  Proxy objects are not :term:`hashable` regardless of the referent; this
    avoids a number of problems related to their fundamentally mutable nature, and
    prevent their use as dictionary keys.  *callback* is the same as the parameter
    of the same name to the :func:`ref` function.
diff --git a/Doc/reference/datamodel.rst b/Doc/reference/datamodel.rst
@@ -388,9 +388,10 @@ Set types
    Frozen sets
       .. index:: object: frozenset
 
-      These represent an immutable set. They are created by the built-in
-      :func:`frozenset` constructor. As a frozenset is immutable and hashable, it can
-      be used again as an element of another set, or as a dictionary key.
+      These represent an immutable set.  They are created by the built-in
+      :func:`frozenset` constructor.  As a frozenset is immutable and
+      :term:`hashable`, it can be used again as an element of another set, or as
+      a dictionary key.
 
    .. % Set types
 
@@ -1242,6 +1243,9 @@ Basic customization
             object.__gt__(self, other)
             object.__ge__(self, other)
 
+   .. index::
+      single: comparisons
+
    These are the so-called "rich comparison" methods, and are called for comparison
    operators in preference to :meth:`__cmp__` below. The correspondence between
    operator symbols and method names is as follows: ``x<y`` calls ``x.__lt__(y)``,
@@ -1256,14 +1260,16 @@ Basic customization
    context (e.g., in the condition of an ``if`` statement), Python will call
    :func:`bool` on the value to determine if the result is true or false.
 
-   There are no implied relationships among the comparison operators. The truth of
-   ``x==y`` does not imply that ``x!=y`` is false.  Accordingly, when defining
-   :meth:`__eq__`, one should also define :meth:`__ne__` so that the operators will
-   behave as expected.
+   There are no implied relationships among the comparison operators. The truth
+   of ``x==y`` does not imply that ``x!=y`` is false.  Accordingly, when
+   defining :meth:`__eq__`, one should also define :meth:`__ne__` so that the
+   operators will behave as expected.  See the paragraph on :meth:`__hash__` for
+   some important notes on creating :term:`hashable` objects which support
+   custom comparison operations and are usable as dictionary keys.
 
-   There are no reflected (swapped-argument) versions of these methods (to be used
-   when the left argument does not support the operation but the right argument
-   does); rather, :meth:`__lt__` and :meth:`__gt__` are each other's reflection,
+   There are no swapped-argument versions of these methods (to be used when the
+   left argument does not support the operation but the right argument does);
+   rather, :meth:`__lt__` and :meth:`__gt__` are each other's reflection,
    :meth:`__le__` and :meth:`__ge__` are each other's reflection, and
    :meth:`__eq__` and :meth:`__ne__` are their own reflection.
 
@@ -1276,14 +1282,15 @@ Basic customization
       builtin: cmp
       single: comparisons
 
-   Called by comparison operations if rich comparison (see above) is not defined.
-   Should return a negative integer if ``self < other``, zero if ``self == other``,
-   a positive integer if ``self > other``.  If no :meth:`__cmp__`, :meth:`__eq__`
-   or :meth:`__ne__` operation is defined, class instances are compared by object
-   identity ("address").  See also the description of :meth:`__hash__` for some
-   important notes on creating objects which support custom comparison operations
-   and are usable as dictionary keys. (Note: the restriction that exceptions are
-   not propagated by :meth:`__cmp__` has been removed since Python 1.5.)
+   Called by comparison operations if rich comparison (see above) is not
+   defined.  Should return a negative integer if ``self < other``, zero if
+   ``self == other``, a positive integer if ``self > other``.  If no
+   :meth:`__cmp__`, :meth:`__eq__` or :meth:`__ne__` operation is defined, class
+   instances are compared by object identity ("address").  See also the
+   description of :meth:`__hash__` for some important notes on creating
+   :term:`hashable` objects which support custom comparison operations and are
+   usable as dictionary keys. (Note: the restriction that exceptions are not
+   propagated by :meth:`__cmp__` has been removed since Python 1.5.)
 
 
 .. method:: object.__hash__(self)
@@ -1293,19 +1300,12 @@ Basic customization
       builtin: hash
       single: __cmp__() (object method)
 
-   Called for the key object for dictionary  operations, and by the built-in
-   function :func:`hash`.  Should return a 32-bit integer usable as a hash value
+   Called for the key object for dictionary operations, and by the built-in
+   function :func:`hash`.  Should return an integer usable as a hash value
    for dictionary operations.  The only required property is that objects which
    compare equal have the same hash value; it is advised to somehow mix together
    (e.g., using exclusive or) the hash values for the components of the object that
-   also play a part in comparison of objects.  If a class does not define a
-   :meth:`__cmp__` method it should not define a :meth:`__hash__` operation either;
-   if it defines :meth:`__cmp__` or :meth:`__eq__` but not :meth:`__hash__`, its
-   instances will not be usable as dictionary keys.  If a class defines mutable
-   objects and implements a :meth:`__cmp__` or :meth:`__eq__` method, it should not
-   implement :meth:`__hash__`, since the dictionary implementation requires that a
-   key's hash value is immutable (if the object's hash value changes, it will be in
-   the wrong hash bucket).
+   also play a part in comparison of objects.
 
    :meth:`__hash__` may also return a long integer object; the 32-bit integer is
    then derived from the hash of that object.
diff --git a/Doc/reference/expressions.rst b/Doc/reference/expressions.rst
@@ -267,7 +267,7 @@ in the new dictionary in the order they are produced.
            hashable
 
 Restrictions on the types of the key values are listed earlier in section
-:ref:`types`.  (To summarize, the key type should be hashable, which excludes
+:ref:`types`.  (To summarize, the key type should be :term:`hashable`, which excludes
 all mutable objects.)  Clashes between duplicate keys are not detected; the last
 datum (textually rightmost in the display) stored for a given key value
 prevails.
diff --git a/Lib/bsddb/dbtables.py b/Lib/bsddb/dbtables.py
@@ -362,7 +362,7 @@ def __new_rowid(self, table, txn) :
         unique = 0
         while not unique:
             # Generate a random 64-bit row ID string
-            # (note: might have <64 bits of randomness
+            # (note: might have <64 bits of true randomness
             # but it's plenty for our database id needs!)
             blist = []
             for x in range(_rowid_str_len):
diff --git a/Lib/contextlib.py b/Lib/contextlib.py
@@ -25,6 +25,10 @@ def __exit__(self, type, value, traceback):
             else:
                 raise RuntimeError("generator didn't stop")
         else:
+            if value is None:
+                # Need to force instantiation so we can reliably
+                # tell if we get the same exception back
+                value = type()
             try:
                 self.gen.throw(type, value, traceback)
                 raise RuntimeError("generator didn't stop after throw()")
diff --git a/Lib/ctypes/test/test_cfuncs.py b/Lib/ctypes/test/test_cfuncs.py
diff --git a/Lib/ctypes/test/test_functions.py b/Lib/ctypes/test/test_functions.py
diff --git a/Lib/test/test_with.py b/Lib/test/test_with.py
diff --git a/Modules/_bsddb.c b/Modules/_bsddb.c
diff --git a/configure b/configure
diff --git a/configure.in b/configure.in
