Composition and inheritance in Python (Smalltalk style)

composition.py

class Base:
    def mul(self, a, b):
        return a * b

    def add(self,a,b):
        return a + b

class Derived(Base):
    def sub(self,a,b):
        return a - b

    def div(self,a,b):
        return a / b


class Composed:
    def __init__(self):
        self.base = Base()

    def sub(self,a,b):
        return a - b

    def div(self,a,b):
        return a / b

    def __getattr__(self, name):
        return getattr(self.base, name)

foo = Derived()
print(foo.sub(1,2))
print(foo.add(1,2))

bar = Composed()
print(bar.sub(1,2))
print(bar.add(1,2))