Worked example of overloading

with_overloading.py

import math
from functools import singledispatch


class Square:
    length: int

    def __init__(self, length=0):
        self.length = length


class Circle:
    radius: int

    def __init__(self, radius=0):
        self.radius = radius


from functools import singledispatch
@singledispatch
def area(any_object):
    raise NotImplementedError


@area.register(Circle)
def _(any_object):
    return math.pi * (math.pow(any_object.radius, 2))


@area.register(Square)
def _(any_object):
    return (math.pow(any_object.length, 2))


my_circle = Circle(6)
my_square = Square(12)

print(area(my_circle))
print(area(my_square))