unicode instance if the argument is not an instance of basestring and
calling __str__ on the argument returns a unicode instance.

conversion using the proper magic slot (e.g., __int__()).  Also move conversion
code out of PyNumber_*() functions in the C API into the nb_* function.

Applied patch #1109424.  Thanks Walter Doewald.

a minor change after the coercion, to accept two objects not necessarily of
the same type but with the same tp_compare.

I need to define it again.  Bite the bullet and define it once as an
extern, _Py_SwappedOp[].

- weakref.ref and weakref.ReferenceType will become aliases for each
  other

- weakref.ref will be a modern, new-style class with proper __new__
  and __init__ methods

- weakref.WeakValueDictionary will have a lighter memory footprint,
  using a new weakref.ref subclass to associate the key with the
  value, allowing us to have only a single object of overhead for each
  dictionary entry (currently, there are 3 objects of overhead per
  entry: a weakref to the value, a weakref to the dictionary, and a
  function object used as a weakref callback; the weakref to the
  dictionary could be avoided without this change)

- a new macro, PyWeakref_CheckRefExact(), will be added

- PyWeakref_CheckRef() will check for subclasses of weakref.ref

This closes SF patch #983019.

The builtin eval() function now accepts any mapping for the locals argument.
Time sensitive steps guarded by PyDict_CheckExact() to keep from slowing
down the normal case.  My timings so no measurable impact.

dynamic embedders of Python.

Closes bug #885293 (thanks, Josiah Carlson).

SF patch 825639
http://mail.python.org/pipermail/python-dev/2003-October/039445.html

[ 784825 ] fix obscure crash in descriptor handling

Should be applied to release23-maint and in all likelyhood
release22-maint, too.

Certainly doesn't apply to release21-maint.

I'm finding some pretty baffling output, like reprs consisting entirely
of three left parens.  At least this will let us know what type the object
is (it's not str -- there's no quote character in the repr).

New tool combinerefs.py, to combine the two output blocks produced via
PYTHONDUMPREFS.

new line.

New pvt API function _Py_PrintReferenceAddresses():  Prints only the
addresses and refcnts of the live objects.  This is always safe to call,
because it has no dependence on Python's C API.

Py_Finalize():  If envar PYTHONDUMPREFS is set, call (the new)
_Py_PrintReferenceAddresses() right before dumping final pymalloc stats.
We can't print the reprs of the objects here because too much of the
interpreter has been shut down.  You need to correlate the addresses
displayed here with the object reprs printed by the earlier
PYTHONDUMPREFS call to _Py_PrintReferences().

  even farther down, to just before the call to
  _PyObject_DebugMallocStats().  This required the following changes:

- pystate.c, PyThreadState_GetDict(): changed not to raise an
  exception or issue a fatal error when no current thread state is
  available, but simply return NULL without raising an exception
  (ever).

- object.c, Py_ReprEnter(): when PyThreadState_GetDict() returns NULL,
  don't raise an exception but return 0.  This means that when
  printing a container that's recursive, printing will go on and on
  and on.  But that shouldn't happen in the case we care about (see
  first bullet).

- Updated Misc/NEWS and Doc/api/init.tex to reflect changes to
  PyThreadState_GetDict() definition.

Arranged that all the objects exposed by __builtin__ appear in the list
of all objects.  I basically peed away two days tracking down a mystery
leak in sys.gettotalrefcount() in a ZODB app (== tons of code), because
the object leaking the references didn't appear in the sys.getobjects(0)
list.  The object happened to be False.  Now False is in the list, along
with other popular & previously missing leak candidates (like None).
Alas, we still don't have a choke point covering *all* Python objects,
so the list of all objects may still be incomplete.

_Py_AddToAllObjects() that simply inserts an object at the front of
the doubly-linked list of all objects.  Changed PyType_Ready() (the
 closest thing we've got to a choke point for type objects) to call
that.

a doubly-linked list, exposed by sys.getobjects().  Unfortunately, it's not
really all live objects, and it seems my fate to bump into programs where
sys.gettotalrefcount() keeps going up but where the reference leaks aren't
accounted for by anything in the list of all objects.

This patch helps a little:  if COUNT_ALLOCS is also defined, from now on
type objects will also appear in this list, provided at least one object
of a type has been allocated.

to more accurately describe what the function does.

Suggested by Thomas Wouters.

Factors out the common case of returning self.

Don't access tp_descr_{get,set} of a descriptor without checking the
flag bits of the descriptor's type.  While we know that the main type
(the type of the object whose attribute is being accessed) has all the
right flag bits (or else PyObject_Generic{Get,Set}Attr wouldn't be
called), we don't know that for its class attributes!

Will backport to 2.2.

tp_as_number directly.

merge_class_dict():  This was missing a decref.

Bugfix candidate.

was broken because new-in-2.3 code added a tp_as_mapping slot to tuples.
Repaired that.

Added basic docs to check_recursion().

The code that intended to exempt tuples and strings was also broken here,
and in 2.2:  these should use PyXYZ_CheckExact(), not PyXYZ_Check() -- we
can't know whether subclass instances are immutable.  This part (and this
part alone) is a bugfix candidate.

Fix infinite recursion which occurred when printing an object
whose __str__() returned self.

Will backport

Py_Init crash".  refchain cannot be cleared because objects can live across
Py_Finalize() and Py_Initialize() if they are kept alive by circular
references.

macros.  The 'op' argument is then the result from PyObject_MALLOC,
and that can of course be NULL.  In that case, PyObject_Init[Var]
would raise a SystemError with "NULL object passed to
PyObject_Init[Var]".  But there's nothing the caller of the macro can
do about this.  So PyObject_Init[Var] should call just PyErr_NoMemory.

Will backport.

Because all built-in tests return bools now, this is the most common
path!

always returns a bool, so avoid calling PyObject_IsTrue() in that
case.

to _PyType_Lookup().

This causes a modest speedup.