# a look at a simple Python class
 
class Animal(object):
    # uses newer class style, inheriting very basic class 'object'
    def __init__(self, animal, sound):
        # __init__() is the 'constructor' of the class instance
        # when you create an instance of Animal you have to supply
        # it with the name and the sound of the animal
        # 'self' refers to the instance
        # if the instance is dog, then
        # name and sound will be that of the dog
        # 'self' also makes name and sound available
        # to all the methods within the class
        self.name = animal
        self.sound = sound
 
    def speak(self):
        # a method's arguments always start with self
        print( "The %s goes %s" % (self.name, self.sound) )
 
 
# create a few class instances
# remember to supply the name and the sound for each animal
dog = Animal("dog", "woof")
cat = Animal("cat", "meeouw")
cow = Animal("cow", "mooh")
 
# now you can call each animals function/method speak()
# by simply connecting instance_name and speak() with a '.'
cow.speak()
cat.speak()
dog.speak()
 
# you can also access variables associated with the instance
# since cow is the instance
# self.sound becomes cow.sound
print(cow.sound)  # --> mooh