from song import Song  # An Album is a collection of songs

class Album:

    """An album is a collection of songs. The Album class defines
       a number of overloaded operators"""

    def __init__(self, s_ist):
        """Constructor"""
        self.songs = []
        for s in s_ist:
            self.songs += [s]

    def __str__(self):
        """Sting representation"""
        ret_str = '++++++++\n'
        for i in range(len(self.songs)):
            ret_str += str(i+1) + ':' + str(self.songs[i])
            ret_str += '\n++++++++\n'
        return ret_str

    def __len__(self):
        """Overload the len() function """
        return len(self.songs)

    def __add__(self, new_song):
        """Overaload the + operator"""
        self.songs += [new_song]
        return self

    def __iadd__(self, new_song):
        """Overload the += operator"""
        self.songs += [new_song]
        return self

    def __contains__(self, a_song):
        """Overload the in operator"""
        return a_song in self.songs