看廖大博客时候看到的一道题，在此记录一下

练习编写杨辉三角的实现，示例代码来自廖雪峰博客

期待输出:

[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]

def triangles():
    L = [1]
    yield L
    while True:
        L1 = [1]
        for i in range(0,len(L)-1):
            L1.append(L[i]+L[i+1])
        L1.append(1)        # 一开始写到 for 里了，结果输出全是 1,观察杨辉三角可知最后应该单独插入一个 1,所以应该写在循环外
        L = L1
        yield L
n = 0
results = []
for t in triangles():
    results.append(t)
    n = n + 1
    if n == 10:
        break
for t in results:
    print(t)
if results == [
    [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]
]:
    print('测试通过!')
else:
    print('测试失败!')