On Fri, 25 Sep 2009 20:15:54 -0700, Chris Rebert wrote: >> Inside MyClass().method(n), I dispatch to either NClass.method() or >> PClass.method() depending on the value of the argument n. The correct >> class is called, but then the *other* class method is called as well. >> E.g. this is what I expect: >> >> MyClass().method(2) >> -> calls PClass.method >> -> calls BaseClass.method >> >> but this is what I get: >> >> MyClass().method(2) >> -> calls PClass method >> -> calls NClass.method >> -> calls BaseClass.method >> >> >> and similarly for negative arguments, swapping PClass and NClass. >> >> First off, is this the expected behaviour? I seems strange to me, can >> somebody explain why it is the nominally correct behaviour? > > Pretty darn sure it's expected. super() follows the MRO, which in this > case is M, P, N, B, o; thus, the super() of an M instance from a P > method is indeed N.
I was expecting super() to look at the class, not the instance. So if I call super(PClass, self), I expected that since PClass does not inherit from NClass, nothing should be inherited from NClass. > This would normally be useful as one typically wants to call the > "parent" methods of all ancestor classes for which the method is > defined, rather than picking-and-choosing as MyClass.method() does. Gotcha. I was expecting super() to call the first matching ancestor method, not all of them. -- Steven -- http://mail.python.org/mailman/listinfo/python-list
