Rich comparison methods don't work in sets?
__peter__ at web.de
Fri Jun 19 21:37:17 CEST 2009
Gustavo Narea wrote:
> I've noticed that if I have a class with so-called "rich comparison"
> (__eq__, __ne__, etc.), when its instances are included in a set,
> set.__contains__/__eq__ won't call the .__eq__ method of the elements
> and thus
> the code below:
> obj1 = RichComparisonClass()
How is RichComparisonClass implemented? Did you provide a __hash__() method
such that obj1 == obj2 implies hash(obj1) == hash(obj2)? This is necessary
for instances of the class to work properly with sets and dicts.
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