[Python-Dev] Multiple inheritance
Paul F. Dubois
Thu, 3 May 2001 09:24:40 -0700
Pardon if this is brief and suggestive only, I am on deadlines.
Super is a mistaken concept in multiple inheritance languages. Fortunately,
Python is not brain-damaged. Its multiple inheritance model can be fixed
easily to be fully capable.
Here is a suggestive example of implementing the Eiffel model (the only one
that is theoretically sound) using "pretend" Python syntax (keyword
conservationists might like "import" where I have "rename"):
1. The simple case, X inherits from Y and in defining foo and bar needs to
use Y's version:
class X (Y rename foo as _sfoo,
bar as _sbar
def foo (self):
Suppose D inherits from B and C, which both inherit from A.
A has a method a1 that is redefined in B but not in C.
D wishes to use both A's version as inherited via C and B's version.
class D (B rename a1 as ba1, C rename a1 as ca1):
can now use self.ca1, self.a1
Renaming is also useful where you inherit from a utility class and the lingo
is different in the class where you want to use it. E.g. class Window (Tree
rename children as subWindows)
Reference: Meyer, B. "Object-Oriented Software Construction", 2nd Edition.