How do overridden method calls from base-class methods work?

Question

According to the docs on inheritance:

Derived classes may override methods of their base classes. Because methods have no special privileges when calling

Answer 1

class Base():
    def m1(self):
        return self.m2()
    def m2(self):
        return 'base'

class Sub(Base):
    def m2(self):
        return 'sub'

b = Base()
s = Sub()
print(b.m1(), s.m1())

prints "base sub"