Python: List all base classes in a hierarchy

Question

Given a class Foo (whether it is a new-style class or not), how do you generate all the base classes - anywhere in the inheritance hierarchy - it issubclass of?

Answer 1

inspect.getclasstree() will create a nested list of classes and their bases.

Answer 2

See the __bases__ property available on a python class, which contains a tuple of the bases classes:

>>> def classlookup(cls):
...     c = list(cls.__bases__)
...     for base in c:
...         c.extend(classlookup(base))
...     return c
...
>>> class A: pass
...
>>> class B(A): pass
...
>>> class C(object, B): pass
...
>>> classlookup(C)
[<type 'object'>, <class __main__.B at 0x00AB7300>, <class __main__.A at 0x00A6D630>]

Answer 3

inspect.getmro(cls) works for both new and old style classes and returns the same as NewClass.mro(): a list of the class and all its base classes.

>>> class A(object):
>>>     pass
>>>
>>> class B(A):
>>>     pass
>>>
>>> import inspect
>>> inspect.getmro(B)
(<class '__main__.B'>, <class '__main__.A'>, <type 'object'>)