Python，求解答，谢谢好心人

s = []
for i in range(1, 2*5):
    if i <= 5 :
        s.append(i)
    else:
        s.pop()
    string = ''.join([str(j) for j in s])
    print(string)

源程序如下：

n = int(input("请输入一个整数:"))
for i in range(1,n+1):
    a = ""
    for j in range(1,i+1):
        a += str(j)
    print(a)
for i in range(n,1,-1):
    a = ""
    for j in range(1,i):
        a += str(j)
    print(a)

运行结果：