Class Inheritance in Python

Question

I'm new to python and trying to get a list of the classes an object's class inherits from. I'm trying to do this using the bases attribute but I'm not having any success. Can someone please help me out?

def foo(C):
     print(list(C.__bases__))

class Thing(object):
    def f(self):
        print("Yo")

class Shape(Thing):
    def l(self):
        print("ain't no thang")

class Circle(Shape):
    def n(self):
        print("ain't no shape")

test = Circle()
foo(test)

Answer 1

Only classes have __bases__; class instances do not. You can get the class object through an instance's __class__: use foo(test.__class__) or foo(Circle).

Answer 2

Use inspect, from documentation

Return a tuple of class cls’s base classes, including cls, in method resolution order. No class appears more than once in this tuple. Note that the method resolution order depends on cls’s type. Unless a very peculiar user-defined metatype is in use, cls will be the first element of the tuple.

>>> import inspect
>>> inspect.getmro(test.__class__)
(<class '__main__.Circle'>, <class '__main__.Shape'>, <class '__main__.Thing'>, <type 'object'>)
>>> 

This traverses up the inheritance hierarchy & prints all classes, including object. Pretty Cool eh ?