On Fri, 01 Apr 2005 23:04:42 GMT, "Raymond Hettinger" <[EMAIL PROTECTED]> wrote:
>[Bengt Richter] >> I wonder if a dict with a general override hook for hashing all keys would be >useful. >> E.g., a dict.__keyhash__ that would take key as arg and default as now >returning key.__hash__() >> but that you could override. Seems like this could potentially be more >efficient than key wrappers, >> and would also make it so you wouldn't have to chase all the affected methods >in doing an idict >> like the above (e.g., get, setdefault, update etc. etc.) > >There has also been a discussion of adding a seqdict that maintains a keys in >insertion order. Another idea was to have a defaultdict that could be >instructed to create values as necessary (either zero for counting or [] for >list building). Putting the three ideas together, perhaps we should write an >extension module with a custom dictionary type with methods/attributes >implementing those ideas. Essentially, the thought is to put all the bells and >whistles in one place. If the extension became popular, it could ultimately >wend its way into the collections module. > >A facetious naming idea would be to call it TrickyDict, a relative to DictMixin >and no relation to a former U.S. president ;-) > >t = TrickyDict() >t.keytransform(str.lower) >t['abC'] = 1 # case insensitive dictionary >assert t['Abc'] == 1 assert t.keys() == ['abC'] # actual keys unchanged (but transformed for hash and cmp) [...] > >Taken together, these six attributes/methods could cover many wished for >features for the 10% of the cases where a regular dictionary doesn't provide >the >best solution. You think as much as 10% ? Regards, Bengt Richter -- http://mail.python.org/mailman/listinfo/python-list
