This derives from this forum post.

class A:
    def __init__(self):
        print("A.__init__")

class B(A):
    def __init__(self):
        print("B.__init__")
        super().__init__()

class C(A):
    def __init__(self):
        print("C.__init__")
        super().__init__()


class D(B,C):
    def __init__(self):
        print("D.__init__")
        super().__init__()

If you issue D() at the REPL you get:

>>> D()
D.__init__
B.__init__
A.__init__
<D object at aac31180>

whereas cPython gives:

>>> D()
D.__init__
B.__init__
C.__init__
A.__init__
<__main__.D object at 0x7f40ecd1a358>
>>> 

A further issue with super() - with single inheritance - is this. Despite numerous successful uses I wrote one class where super() returned an empty string. Unfortunately any attempt to produce a test case failed. I appreciate that's a lousy bug report but I thought it worth mentioning if the code is being reviewed.