从上学时开始，通常是用C来求阶乘，今天无事，用Python写了一下，主要在于学习lambda和reduce这两个函数的使用。
实现：
[python]
#!/usr/bin/env python #-*- coding: utf-8 -*- import time def test_factorial_reduce(): ''''' Function:使用reduce函数 Input：NONE Output: NONE author: socrates blog: date:2012-02-19 ''' time_begin = time.clock() print reduce(lambda x,y:x*y, range(1, long(raw_input("please input a number ( > 0):")))) print "Use time: %s" % (time.clock() - time_begin) return; def test_factorial_math(): ''''' Function:使用math库函数 Input：NONE Output: NONE author: socrates blog: date:2012-02-19 ''' import math time_begin = time.clock() print math.factorial(long(raw_input("please input a number ( > 0):"))) print "Use time: %s" % (time.clock() - time_begin) if __name__ == '__main__': print '*' * 50 + "Use reduce" + '*' * 50 test_factorial_reduce() print '*' * 50 + "Use math api" + '*' * 50 test_factorial_math()测试：