I'm subclassing set, and redefining __eq__(). I'd appreciate any relevant advice.
>>> class mySet(set): ... def __eq__(self, other): ... print "called mySet.__eq__()!" ... if isinstance(other, (set, frozenset)): ... return True ... return set.__eq__(self, other) ... I stipulate that this is a weird thing to do, but this is a toy class to avoid the lengthy definition of the class I actually want to write. Now I want the builtin set and frozenset types to use the new __eq__() with mySet symmetrically. >>> mySet() == set([1]) called mySet.__eq__()! True >>> mySet() == frozenset([1]) called mySet.__eq__()! True >>> set([1]) == mySet() called mySet.__eq__()! True >>> frozenset([1]) == mySet() False frozenset doesn't use mySet.__eq__() because mySet is not a subclass of frozenset as it is for set. I've tried a number of techniques to mitigate this issue. If I multiple-inherit from both set and frozenset, I get the instance lay-out conflict error. I have similar problems setting mySet.__bases__ directly, and hacking mro() in a metaclass. So far nothing has worked. If it matters, I'm using 2.6, but I can change versions if it will help. Should I give up on this, or is there something else I can try? Keep in mind, I must redefine __eq__(), and I'd like to be able to compare instances of the class to both set and frozenset instances. cheers, Jess -- http://mail.python.org/mailman/listinfo/python-list
