如何使用For循环找到N facorial？

Question

可能重复:
Python中的因子函数

我需要在python中编写一个返回N!的程序,而不使用factorial函数.我有一个程序到目前为止,但我一直收到错误说,local variable "fact" is assigned but never used.fact = 1分配后如何使用？

from pylab import *  


def factorial(n):
    fact = 1

for i in range(n):
    print("i = ", i)
    fact = fact * i

print("The factorial of " + str(n) + " is: " + str(fact))

Answer 1

In [37]: def fact(n):
    fac=1
    for i in range(2,n+1):
        fac *=i
    return fac
   ....: 


In [43]: fact(5)
Out[43]: 120

In [44]: fact(6)
Out[44]: 720