def triangles(): ? ?L = [1] ? ?while True: ? ? ? ? ? ?yield L ?? ? ? ? ?L.append(0)? ? ? ? ?L = [L[i - 1] + L[i] for i in range(len(L))]?n = 0for t in triangles(): ? ?print(t) ? ?n = n + 1 ? ?if n == 10: ? ? ? ?breakL = [L[i - 1] + L[i] for i in range(len(L))] 這一段列表生成怎么理解，i一開始不應(yīng)該是0嗎，那L[i-1]不就是L[-1]？哪里理解的不對呢