python3 将阶乘改成函数形式进行调用的操作

def jc(num):
  if num==1:
    return 1
  else:
    return num*jc(num-1)
print(jc(5)) #返回120

def func(num):
  '求一个数字的阶乘，例如5！'
  sum=1
  for i in range(1,num+1):
    sum=sum*i #可以简化sum*=i
  return sum
func(5)
print(func(5))#返回120

from functools import reduce
print(reduce(lambda x,y:x*y,range(1,6)))

from functools import reduce
def my_factorial(x):
  if x < 0:
    raise ValueError('参数不能为负数')
  return reduce(lambda x, y: x*y, range(1, x+1)) if x != 0 else 1

>>> for i in range(10):
...   print(my_factorial(i), end=' ')
>>> 1 1 2 6 24 120 720 5040 40320 362880