Rosalind全排列的问题

这里我们需要实现全排列

import itertools
set1 = []
a = 1
n = int(input("请输入一个整数："))
**for i in range (1,n+1):
    a = a * i
print(a)**
for i in range(1,n+1):
    set1.append(i)
b = itertools.permutations(set1,n)
for one in list(b):
    print(' '.join(map(str,list(one))))