class Parent(object):

    def _extra_functions(self):
        pass

def function(self):
    do_something()
self.extra_functions()


class Child1(Parent):

    def _extra_functions(self):
        do_something_else_1()


class Child2(Parent):

    def _extra_functions(self):
        do_something_else_2()
How to enforce (with a warning) that parent functions are called by the children that override them?