"Duck typing" = Another way to achieve polymorphism besides Inheritance
Object must have the minimum necessary attributes/methods
"If it looks like a duck and quacks like a duck, it must be a duck."

class Animal:
alive = True

class Dog(Animal):
def speak(self):
print("WOOF!")

class Cat(Animal):
def speak(self):
print("MEOW!")

class Car:
alive = True

def speak(self):
print("HONK!")

animals = [Dog(), Cat(), Car()]

for animal in animals:
animal.speak()
print(animal.alive)