lost Hashability with __cmp__
mwh at python.net
Wed Jan 29 15:33:19 CET 2003
Martin Schmettow <martin.schmettow at bibliothek.uni-regensburg.de> writes:
> Hi all.
> I declared a __cmp__ for a class. Now I get an TypeError: unhashable
> instance if I use objects of this class as keys in a dictionary.
> Can someone explain why and how I can gain back hashability?
Define a __hash__ method. Make sure that instances that __cmp__ equal
generate the same hash code.
112. Computer Science is embarrassed by the computer.
-- Alan Perlis, http://www.cs.yale.edu/homes/perlis-alan/quotes.html
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