python中reduce实现阶乘

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

或者用lambda函数进一步简化成:

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