Hi! I am trying to change the hash function of an instance after it is created. I tried to override the __hash__ attribute of the instance with a bound method created from a custom hash function. It worked for <type 'instance'>, but not for instances of <type 'object'>:
sage: def my_hash(self): ....: print "custom hash" ....: return id(self) ....: sage: class Foo: ....: def __hash__(self): ....: print "Foo's hash" ....: return id(self) ....: sage: class Bar(object): ....: def __hash__(self): ....: print "Bar's hash" ....: return id(self) ....: sage: f = Foo() sage: b = Bar() sage: import types sage: f.__hash__ = types.MethodType(my_hash, f, Foo) sage: b.__hash__ = types.MethodType(my_hash, b, Bar) Now, f uses the custom hash: sage: hash(f) custom hash 93075504 But b is still using the hash function from its class: sage: hash(b) Bar's hash 94410128 sage: type(f) <type 'instance'> sage: type(b) <class '__main__.Bar'> Experts, please tell me why it doesn't work, and how to work around (if possible). Best regards, Simon -- To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org
