input: Write a function to create a Python class named Song that has two instance variables, title and artist, and three methods, str(), eq(), and length(). The str() method should return a string representation of the song in the format "Title: {title}\nArtist: {artist}". The eq() method should check if two Song objects are equal by comparing their title and artist. The length() method should return the length of the title string.
  
  class Song:
      def __init__(self, title, artist):
          self.title = title
          self.artist = artist
    
      def __str__(self):
          return f'Title: {self.title}\nArtist: {self.artist}'
      
      def __eq__(self, other):
          return self.artist == other.artist and self.title == other.title
  
      def length(self):
          return len(self.title)
  
  assert str(Song("Bohemian Rhapsody", "Queen")) == 'Title: Bohemian Rhapsody\nArtist: Queen'
  assert Song("Bohemian Rhapsody", "Queen") == Song("Bohemian Rhapsody", "Queen")
  assert Song("Bohemian Rhapsody", "Queen") != Song("Another Song", "Queen")
  assert Song("Bohemian Rhapsody", "Queen").length() == 16
  assert Song("A", "B").length() == 1
output: class Song:
      def __init__(self, title, artist):
          self.title = title
          self.artist = artist
    
      def __str__(self):
          return f'Title: {self.title}\nArtist: {self.artist}'
      
      def __eq__(self, other):
          return self.artist == other.artist and self.title == other.title
  
      def length(self):
          return len(self.title)