Python-按元素添加2个列表？

Question

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？

Answer 1

使用map有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