Calculates the factorial of a value

#Calculate the factorial of num

def factorial(num):
    i, multiply = 1, 1
    while i < num+1:
        multiply *= i
        i += 1
    yield multiply

if __name__ == '__main__':
    # 生成器
    user_input = input('请输入你需要计算的阶乘')
    f = factorial(int(user_input))
    while True:
        try:
            x = next(f)
        except StopIteration as e:
            print(x)
            break

# 数学类

import math
print(math.factorial(int(user_input)))