How to test if python class parent has method defined?

Question

I have a subclass that may have a method 'method_x' defined. I want to know if 'method_x' was defined somewhere else up the class hierarchy.

If I do:

hasattr(self, 'method_x')

I'll get a truth value that also looks at any methods defined for the subclass. How do I limit this to just inquire as to whether or not that method was defined higher up the class chain?

Answer 1

If you're using Python 3, you can supply super() to the object parameter of hasattr.

For example:

class TestBase:
    def __init__(self):
        self.foo = 1

    def foo_printer(self):
        print(self.foo)


class TestChild(TestBase):
    def __init__(self):
        super().__init__()
        print(hasattr(super(), 'foo_printer'))

test = TestChild()

With Python 2, it's similar, you just have to be more explicit in your super() call.

class TestBase(object):
    def __init__(self):
        self.foo = 1

    def foo_printer(self):
        print(self.foo)


class TestChild(TestBase):
    def __init__(self):
        super(TestChild, self).__init__()
        print(hasattr(super(TestChild, self), 'foo_printer'))


test = TestChild()

Both 2 and 3 will work with multiple levels of inheritance and mixins.