python实现杨辉三角

主要思想是进行错位相加：

def f():    L = [1]    m = 0    while m < len(L):        yield L        L = [1] + [L[x]+L[x+1] for x in range(len(L)-1)] +[1]    return 'done'# 调用t = 0for n in f():    print(n)    t =  t + 1    if t == 10 :        break

结果：

[1][1, 1][1, 2, 1][1, 3, 3, 1][1, 4, 6, 4, 1][1, 5, 10, 10, 5, 1][1, 6, 15, 20, 15, 6, 1][1, 7, 21, 35, 35, 21, 7, 1][1, 8, 28, 56, 70, 56, 28, 8, 1][1, 9, 36, 84, 126, 126, 84, 36, 9, 1]