Python __hash__ for equal value objects

Python __hash__ for equal value objects

Say I have some Person entities and I want to know if one is in a list:
person in people?
I don't care what the 'object's ID' is, just that their properties are the
same. So I put this in my base class:
# value comparison only
def __eq__(self, other):
return (isinstance(other, self.__class__) and self.__dict__ ==
other.__dict__)
def __ne__(self, other):
return not self.__eq__(other)
But to be able to test for equality in sets, I also need to define hash So...
# sets use __hash__ for equality comparison
def __hash__(self):
return (
self.PersonID,
self.FirstName,
self.LastName,
self.etc_etc...
).__hash__()
The problem is I don't want to list every property, and I don't want to
modify the hash function every time the properties change.
So is it okay to do this?
# sets use __hash__ for equality comparison
def __hash__(self):
values = tuple(self.__dict__.values())
return hash(values)
Is this sane, and not toooo much of a performance penalty? In a web-app
situation.
Thanks muchly.