杨辉三角Python输出个菱形，就是上下对称那种

杨辉三角Python输出个菱形，就是上下对称那种，也可以左右对称，重复输出

layer = int(input("请输入层数："))
while layer & 1 == 0:
    layer = int(input("层数必须是奇数层！"))

for i in range(1, layer//2 + 2):
    print(" "* (layer - i), end="")
    print("*"* (2*i - 1))

for i in range(layer//2, 0, -1):
    print(" "* (layer - i), end="")
    print("*"* (2*i - 1))