code: def randomize(self):
          
          random_pfm = [[c for c in row] for row in self.pfm]
          random.shuffle(random_pfm)
          m = Motif(pfm=random_pfm)
          m.id = "random"
          return m
docs: Create a new motif with shuffled positions.
  
          Shuffle the positions of this motif and return a new Motif instance.
  
          Returns
          -------
          m : Motif instance
              Motif instance with shuffled positions.