python中reduce实现阶乘

from functools import reducedef prod(L):    def myCheng(x,y):        return x*y     return reduce(myCheng,L)print("3*5*7*9=",prod([3,5,7,9]))

或者用lambda函数进一步简化成:

def prod(L):    return reduce(lambda x,y:x*y,L)print("3*5*7*9=",prod([3,5,7,9]))