In Python can one implement mixin behavior without using inheritance?

Question

Is there a reasonable way in Python to implement mixin behavior similar to that found in Ruby -- that is, without using inheritance?

class Mixin(object):
    def         


        

Answer 1

Composition? It seems like that would be the simplest way to handle this: either wrap your object in a decorator or just import the methods as an object into your class definition itself. This is what I usually do: put the methods that I want to share between classes in a file and then import the file. If I want to override some behavior I import a modified file with the same method names as the same object name. It's a little sloppy, but it works.

For example, if I want the init_covers behavior from this file (bedg.py)

import cove as cov


def init_covers(n):
    n.covers.append(cov.Cover((set([n.id]))))
    id_list = []
    for a in n.neighbors:
        id_list.append(a.id)
    n.covers.append(cov.Cover((set(id_list))))

def update_degree(n):
    for a in n.covers:
        a.degree = 0
        for b in n.covers:
            if  a != b:
                a.degree += len(a.node_list.intersection(b.node_list))    

In my bar class file I would do: import bedg as foo

and then if I want to change my foo behaviors in another class that inherited bar, I write

import bild as foo

Like I say, it is sloppy.