On 12/13/06, Walter Dörwald <[EMAIL PROTECTED]> wrote: > I tried to reimplement weakref.WeakValueDictionary as a subclass of > dict. The test passes except for one problem: To compare results > test_weakref.py converts a weakdict to a real dict via dict(weakdict). > This no longer works because PyDict_Merge() does a PyDict_Check() on the > argument and then ignores all overwritten methods. (The old version > worked because UserDict.UserDict was used). > > The simplest solution is to replace the PyDict_Check() call with > PyDict_CheckExact(), but this might slow things down too much, because > the fallback code basically does: > > for key in iter(arg.keys()): > self[key] = arg.__getitem__(key) > > Why can't we use: > > for key in iter(arg): > self[key] = arg.__getitem__(key) > > instead?
The only reason I can think of is backwards compatibility: not all "mappings" created pre-2.2 would support iteration. Maybe you could check for a tp_iter slot and if non-NULL use the latter otherwise use the original fallback? -- --Guido van Rossum (home page: http://www.python.org/~guido/) _______________________________________________ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
