Ducks, quack!

ducks.py

# First, let's define what will end up being our "super class."
class Duck():
  def __init__(self, name=None):
      self.name = name
  def quack(self):
      print("QUACK! My name is {}.".format(self.name))

# all ducks can quack, and can say their name.
ducky = Duck("Ducky")
ducky.quack()
# >> "QUACK! My name is Ducky."

# Mallards are Ducks, too --
class Mallard(Duck):
    pass

# to make Mallard inherit from Duck, we define the class this way.
# now, Mallards can quack, even though we didn't "teach" them how: they are Ducks.
ducky2 = Mallard("ducky2")
ducky2.quack()
# >> "QUACK! My name is ducky2."

# But Mallards don't quack, they honk.
class Mallard2(Duck):
    def quack(self):
        print("HONK! My name is {}.".format(self.name))
        
# This method will completely override the one defined in the parent class, Duck.
mallard = Mallard2("mallard_duck")
mallard.quack()
# >> "HONK! My name is mallard_duck."

# Some ducks quack normally, but add some more information.
class Darkwing(Duck):
    def quack(self):
        super(Darkwing, self).quack()
        print("Let's get dangerous.")

dwd = Darkwing("DWD")
dwd.quack()
# >> "Quack! My name is dwd."
# >> "Let's get dangerous."

# This way lets us call both the method we define on the child class, and the 
# original parent class method.