import functoolssum = 0for i in range(1,21): sum = sum + functools.reduce(lambda x,y: x*y, range(1, i+1))print(sum)import functoolsdef f(n): if n == 1: return 1 else: return functools.reduce(lambda x,y: x*y, range(1, n+1)) + f(n-1)print(f(20))def plus(n): if n == 1: return 1 else: return reduce(lambda x,y: x*y, range(1,n+1)) + plus(n-1)print plus(20)sum = 0x = 1for i in range(1,21): x = x * i sum = sum + xprint(sum)【Python3练习题 020】 求1+2!+3!+...+20!的和
原文：https://www.cnblogs.com/jackzz/p/9125471.html