python中reduce實現階乘

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函數進一步簡化成:

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