1.使用for-for循环语句：

border_num=int(input('请输入要打印的层数n:'))

for i in range(1,border_num+1):

    for j in range(border_num-i):

        print(' ',end=' ')

    for k in range(1,i+1):

        print(k,end=' ')

    for r in range(i-1,0,-1):

        print(r,end=' ')

    print()

2.结果如图（打印行数用键盘输入）