* Check the found object for a None value during a contains/has_key
lookup. Perhaps it will help the OP who is likely suffering from an
occassional GC or threading object deletion after self.data is checked.
* Complete the previous patch by removing the unnecessary indirection
for weak dict iterators. Makes the code cleaner and more readable.
- 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.
(Championed by Bob Ippolito.)
The update() method for mappings now accepts all the same argument forms
as the dict() constructor. This includes item lists and/or keyword
arguments.
Someone review this, please! Final releases are getting close, Fred
(the weakref guy) won't be around until Tuesday, and the pre-patch
code can indeed raise spurious RuntimeErrors in the presence of
threads or mutating comparison functions.
See the bug report for my confusions: I can't see any reason for why
__delitem__ iterated over the keys. The new one-liner implementation
is much faster, can't raise RuntimeError, and should be better-behaved
in all respects wrt threads.
New tests test_weak_keyed_bad_delitem and
test_weak_keyed_cascading_deletes fail before this patch.
Bugfix candidate for 2.2.3 too, if someone else agrees with this patch.
* Adds missing pop() methods to weakref.py
* Expands test suite to broaden coverage of objects with
a mapping interface.
Contributed by Sebastien Keim.
depending on the cycle detector code in the library implementation.
This is a *slightly* different patch than SF patch #417795, but takes
the same approach. (This version avoids calling the __len__() method of
the dict in the remove() functions.)
This closes SF patch #417795.
Weak*Dictionary.update(): No longer create a temporary list to hold the
things that will be stuffed into the underlying dictionary. This had
been done so that if any of the objects used as the weakly-held value
was not weakly-referencable, no updates would take place (TypeError
would be raised). With this change, TypeError will still be raised
but a partial update could occur. This is more like other .update()
implementations.
Thoughout, use of the name "ref" as a local variable has been removed. The
original use of the name occurred when the function to create a weak
reference was called "new"; the overloaded use of the name could be
confusing for someone reading the code. "ref" used as a variable name
has been replaced with "wr" (for 'weak reference').
Georg Brandl
Andrew M. Kuchling
Raymond Hettinger
Fred Drake
Walter Dörwald
Tim Peters
Guido van Rossum
Skip Montanaro
Martin v. Löwis