python练习题2-杨辉三角生成器

def PascalTriangles(n):
    L=[1]
    while len(L) <= n:
        yield L
        L=[L[i]+L[i+1] for i in range(len(L)-1)]
        L.insert(0,1)
        L.append(1)

测试

for i in PascalTriangles(10):
    print(i)

[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]