class Song(object):
	"""docstring for Song"""
	def __init__(self, lyrics):
		super(Song, self).__init__()
		self.lyrics = lyrics

	def sing_me_a_song(self):
		for line in self.lyrics:
			print(line)


happy_bday = Song(["Happy birthday to you", "I don't want to get sued","So I'll stop right there"])

bulls_on_parade = Song(["They rally around tha family","With pockets full of shells"])

happy_bday.sing_me_a_song()

bulls_on_parade.sing_me_a_song()

class Song(object):

    def __init__(self, disk):
        self.index = 0
        self.disk = disk
        self.jump()

    def next(self):
        ''' next song. '''
        self.index = (self.index + 1) % len(self.disk)
        self.jump()

    def prev(self):
        ''' prev song. '''
        self.index = (self.index - 1) % len(self.disk)
        self.jump()

    def jump(self):
        ''' jump to the song. '''
        self.lyrics = self.disk[self.index]

    def sing_me_a_song(self):
        for line in self.lyrics:
            print(line)

# construct a disk
song1 =  ["Happy birthday to you",
"I don't want to get sued",
"So I'll stop right there"]

song2 = ["They rally around the family",
"With pockets full of shells"
]

song3 = ["Never mind I find",
"Some one like you"
]

disk = [song1, song2, song3]

mycd = Song(disk)
mycd.sing_me_a_song()

mycd.next()
mycd.sing_me_a_song()

mycd.next()
mycd.sing_me_a_song()

mycd.next()
mycd.sing_me_a_song()

mycd.prev()
mycd.sing_me_a_song()

mycd.prev()
mycd.sing_me_a_song()

mycd.prev()
mycd.sing_me_a_song()

mycd.prev()
mycd.sing_me_a_song()