如何调用父类的__repr__？

Question

So the situation I want to resolve is pretty simple. Say I have a subclass C that extends parents B and A . Parents B , and A each have their own __repr__ methods. When I print C , the __repr__ method of parent A is always invoked, but I want to invoke parent B 's.

How can I do this?

Answer 1

Assume A is defined like this:

class A():
    def __repr__(self):
        return "This is A"

and B is defined similarly:

class B():
    def __repr__(self):
        return "This is B"

while C is defined like so:

class C(A, B):
    def __init__(self):
        pass

or something similar. print A() will yield This is A , while the same for B will yield This is B . print C() will, as you describe, give This is A . However, if you just change the order of C 's inheritance:

class C(B, A): # change order of A and B
    def __init__(self):
        pass

then print C() will give you This is B . Simple as that.

Answer 2

If all I wanted was to call an inherited class's repr I would just do:

class C(B, A): # whatever order
    def __repr__(self):
        return A.__repr__(self)

I had a case similar, but slightly different to this question. I wanted to print the default repr of an inherited class. For me class C was dynamically defined with B being a mixin class, but I wanted to show the name and module of the "main" class A. I ended up with this solution.

class C(B, A):
    def __repr__(self):
        '''Override repr to show the name and path of the main cls.'''
        return '<{} {}.{} object at {}>'.format(
            self.__class__.__name__,
            A.__module__,
            A.__name__,
            hex(id(self)))