class Liste: """une liste chaînée""" def __init__(self): self.tete = None def est_vide(self): return self.tete is None def ajoute(self, x): self.tete = Cellule(x, self.tete) def __len__(self): return longueur(self.tete) def __getitem__(self, n): return nieme_element(n, self.tete) def reverse(self): self.tete = renverser(self.tete) def __add__(self, lst): r = Liste() r.tete = concatener(self.tete, lst.tete) return r