我现在有了:
list1 = [1, 2, 3] list2 = [4, 5, 6]
我希望有:
[1, 2, 3] + + + [4, 5, 6] || || || [5, 7, 9]
只是两个列表的元素加法。
我当然可以迭代两个列表,但是我不想这样做。
什么是最Python的方式这样做的?
使用map有operator.add:
operator.add
>>> from operator import add >>> list( map(add, list1, list2) ) [5, 7, 9]
或zip具有列表理解:
>>> [sum(x) for x in zip(list1, list2)] [5, 7, 9]
时序比较:
>>> list2 = [4, 5, 6]*10**5 >>> list1 = [1, 2, 3]*10**5 >>> %timeit from operator import add;map(add, list1, list2) 10 loops, best of 3: 44.6 ms per loop >>> %timeit from itertools import izip; [a + b for a, b in izip(list1, list2)] 10 loops, best of 3: 71 ms per loop >>> %timeit [a + b for a, b in zip(list1, list2)] 10 loops, best of 3: 112 ms per loop >>> %timeit from itertools import izip;[sum(x) for x in izip(list1, list2)] 1 loops, best of 3: 139 ms per loop >>> %timeit [sum(x) for x in zip(list1, list2)] 1 loops, best of 3: 177 ms per loop