python：用 reduce 函数计算阶乘

编写?compute_factorial.py 如下

# -*- coding: utf-8 -*-
""" 计算阶乘 factorial """
import sys
from functools import reduce
#help(reduce)

if len(sys.argv) ==2:
    n = int(sys.argv[1])
else:
    print('usage: python compute_factorial.py n ')
    sys.exit(1)

#n = 30
factorial = reduce(lambda x,y: x*y, range(1,n+1))
print(f"{n}！= {factorial}")

运行 python?compute_factorial.py 30

请参阅：Python 中reduce()与lambda函数详解