hack, and it's even more disgusting than a PyInstance_Check() call.
If the tp_compare slot is the slot used for overrides in Python,
it's always called.
Add some tests that show what should work too.
and are lists, and then just the string elements (if any)).
There are good and bad reasons for this. The good reason is to support
dir() "like before" on objects of extension types that haven't migrated
to the class introspection API yet. The bad reason is that Python's own
method objects are such a type, and this is the quickest way to get their
im_self etc attrs to "show up" via dir(). It looks much messier to move
them to the new scheme, as their current getattr implementation presents
a view of their attrs that's a untion of their own attrs plus their
im_func's attrs. In particular, methodobject.__dict__ actually returns
methodobject.im_func.__dict__, and if that's important to preserve it
doesn't seem to fit the class introspection model at all.
Both int and long multiplication are changed to be more careful in
their assumptions about when one of the arguments is a sequence: the
assumption that at least one of the arguments must be an int (or long,
respectively) is still held, but the assumption that these don't smell
like sequences is no longer true: a subtype of int or long may well
have a sequence-repeat thingie!
keys are true strings -- no subclasses need apply. This may be debatable.
The problem is that a str subclass may very well want to override __eq__
and/or __hash__ (see the new example of case-insensitive strings in
test_descr), but go-fast shortcuts for strings are ubiquitous in our dicts
(and subclass overrides aren't even looked for then). Another go-fast
reason for the change is that PyCheck_StringExact() is a quicker test
than PyCheck_String(), and we make such a test on virtually every access
to every dict.
OTOH, a str subclass may also be perfectly happy using the base str eq
and hash, and this change slows them a lot. But those cases are still
hypothetical, while Python's own reliance on true-string dicts is not.
just by doing type(f) where f is any file object. This left a hole in
restricted execution mode that rexec.py can't plug by itself (although it
can plug part of it; the rest is plugged in fileobject.c now).
on to the tp_new slot (if non-NULL), as well as to the tp_init slot (if
any). A sane type implementing both tp_new and tp_init should probably
pay attention to the arguments in only one of them.
with the same value instead. This ensures that a string (or string
subclass) object's ob_sinterned pointer is always a str (or NULL), and
that the dict of interned strings only has strs as keys.
+ These were leaving the hash fields at 0, which all string and unicode
routines believe is a legitimate hash code. As a result, hash() applied
to str and unicode subclass instances always returned 0, which in turn
confused dict operations, etc.
+ Changed local names "new"; no point to antagonizing C++ compilers.
subclasses, all "the usual" ones (slicing etc), plus replace, translate,
ljust, rjust, center and strip. I don't know how to be sure they've all
been caught.
Question: Should we complain if someone tries to intern an instance of
a string subclass? I hate to slow any code on those paths.
tuple(i) repaired to return a true tuple when i is an instance of a
tuple subclass.
Added PyTuple_CheckExact macro.
PySequence_Tuple(): if a tuple-like object isn't exactly a tuple, it's
not safe to return the object as-is -- make a new tuple of it instead.
Given an immutable type M, and an instance I of a subclass of M, the
constructor call M(I) was just returning I as-is; but it should return a
new instance of M. This fixes it for M in {int, long}. Strings, floats
and tuples remain to be done.
Added new macros PyInt_CheckExact and PyLong_CheckExact, to more easily
distinguish between "is" and "is a" (i.e., only an int passes
PyInt_CheckExact, while any sublass of int passes PyInt_Check).
Added private API function _PyLong_Copy.
of PyMapping_Keys because we know we have a real dict. Tolerate that
objects may have an attr named "__dict__" that's not a dict (Py_None
popped up during testing).
test_descr.py, test_dir(): Test the new classic-class behavior; beef up
the new-style class test similarly.
test_pyclbr.py, checkModule(): dir(C) is no longer a synonym for
C.__dict__.keys() when C is a classic class (looks like the same thing
that burned distutils! -- should it be *made* a synoym again? Then it
would be inconsistent with new-style class behavior.).
bag. It's clearly wrong for classic classes, at heart because a classic
class doesn't have a __class__ attribute, and I'm unclear on whether
that's feature or bug. I'll repair this once I find out (in the
meantime, dir() applied to classic classes won't find the base classes,
while dir() applied to a classic-class instance *will* find the base
classes but not *their* base classes).
Please give the new dir() a try and see whether you love it or hate it.
The new dir([]) behavior is something I could come to love. Here's
something to hate:
>>> class C:
... pass
...
>>> c = C()
>>> dir(c)
['__doc__', '__module__']
>>>
The idea that an instance has a __doc__ attribute is jarring (of course
it's really c.__class__.__doc__ == C.__doc__; likewise for __module__).
OTOH, the code already has too many special cases, and dir(x) doesn't
have a compelling or clear purpose when x isn't a module.
mapping object", in the same sense dict.update(x) requires of x (that x
has a keys() method and a getitem).
Questionable: The other type constructors accept a keyword argument, so I
did that here too (e.g., dictionary(mapping={1:2}) works). But type_call
doesn't pass the keyword args to the tp_new slot (it passes NULL), it only
passes them to the tp_init slot, so getting at them required adding a
tp_init slot to dicts. Looks like that makes the normal case (i.e., no
args at all) a little slower (the time it takes to call dict.tp_init and
have it figure out there's nothing to do).
when an unbound method of class A is stored as a class variable of
class B, and class B is *not* a subclass of class A, that method
should *not* get bound to B instances.
+ test_compare. While None compares less than anything else, it's not
always the case that None has the smallest id().
+ test_descr. The output of %p (pointer) formats varies across platforms.
In particular, on Windows it doesn't produce a leading "0x".
- Remove various 'global' directives and move some global definitions
inside the test functions that use them -- we have nested scopes so
the old hacks using globals are no longer needed.
Guido van Rossum
Tim Peters