打印星形三角

# 使用while，完成图形的输出
i = 1
k = 5
while i < 6:
    j = 1
    while j <= i:
        print('*', end=' ')
        j += 1
    print('\n')
    i += 1
while k > 0:
    j = 1
    while j < k:
        print('*', end=' ')
        j += 1
    print('\n')
    k -= 1

# 最大星星数
my_num = 5
# 循环次数
row_index = 1

while row_index <= 2 * my_num - 1:
    # 定义一个列数
    col_index = 1
    # 完成打印上半部分
    if row_index <= my_num:
        while col_index <= row_index:
            print("*", end="")
            col_index += 1
    else:
        # 完成打印下半部分
        while col_index <= 2 * my_num - row_index:
            print("*", end="")
            col_index += 1
    print()
    row_index += 1