python 三角形

layer = int(input("请输入你要打印的行数:"))
for i in range(1,layer+1):
#计算空格的个数
    spce_num = layer - i
    for j in range(0,spce_num):
        print(" ",end="")
 #计算*个数
    star_num = 2 * i - 1
    for j in range(0,star_num):
        print("*", end="")
    print("")