# There's no java-like rule here
# You can put class squirrel in a file called squirrel if you like, but you don't have to
class squirrel:
    # These are class-level variables
    # "properties"
    # private: # Python doesn't have private
    name = ""
    age = 0
    def __init__(self, name_param):
        self.name = name_param
        self.age = 0
        # Don't really use print here
        # It's just to show what is going on
        print("A new squirrel!  Name is ", self.name)

    def birthday(self):
        self.age += 1
        print("It's ", self.name, "'s birthday!  New age ", self.age)
    
    # Since Python doesn't have private, we don't need this
    def set_age(self, newage):
        self.age = newage


class squirrel_collection:
    squirrels = []
    place = 0
    def add(self, squirrel):
        self.squirrels.append(squirrel)

    def birthday(self):
        for sq in self.squirrels:
            sq.birthday()

    def get_iterator(self):
        def iterator():
            self.place += 1
            if self.place >= len(self.squirrels):
                return None
            return self.squirrels[self.place]
        self.place = -1
        return iterator