How to order base classes?

[Steven D'Aprano]

On Fri, 24 Dec 2010 03:36:28 +0000, kj wrote:

> How should one go about deciding the ordering of base classes?

There is no general way for doing so. You need to consider the actual 
functionality of the methods involved. Consider a method spam() of class 
C that inherits from both A and B. To be completely general, you might 
have any of the following situations:

C.spam() overloads A.spam() followed by B.spam()
C.spam() overloads B.spam() followed by A.spam()
C.spam() overloads A.spam() and overrides B.spam()
C.spam() overloads B.spam() and overrides A.spam()
C.spam() overrides both A.spam() and B.spam()

(where I use "overload" to mean "modify the behaviour of", and "override" 
to mean "change the behaviour completely" -- basically, overloading will 
call the superclass' method, while overriding will not.)

And (again, we're being completely general) whatever choice you make for 
C.spam() may not be valid for C.ham(), which could behave completely 
differently.


The question you ask can only be answered in reference to a specific 
class with specific methods. There is no general principle, it depends 
entirely on the problem being solved.


-- 
Steven