Multiple inheritance can be very useful where you really need it, but it also complicates your code. I believe it should be used rarely, but there are plenty of Python programmers who believe it should never be used. The most common use of multiple inheritance is to provide mixin functionality. It is often used in a similar way to interfaces in languages like C#.
Simon Segal has written a blog entry describing multiple inheritance in IronPython, and how it interacts with inheriting from .NET types:
Question: Does IronPython support Multiple Inheritance / Mixins?In IronPython you can create Python classes that inherit from .NET types and other Python classes, but you can't simultaneously inherit from multiple .NET types. This allows you to create C# classes that you use as mixins from your IronPython code.
Question: Can I use my C# classes from IronPython (in the IP runtime)?
Question: So, I should be able to use my C# classes in a multiple inheritance scenario from IronPython?