根据项条件在两个列表中查找索引

时间:2012-04-12 17:06:19

标签: python list data-structures indexing

让我们说我有两个清单。它们是从-5到5的书籍评级列表。

我想知道list1的元素是>= 1和list2的元素== 0,例如。

list1 = [3, 3, 1, 0, 3, 0, 3, 0, 0, -3, 0, 5, 3, 0, 1, 0, 0, 5, 3, 0, 0, 0, 0, 1, 0, 3, 0, 1, 0, 0, 3, 5, 3, 3, 0, 0, 0, 5, 0, 5, 0, 3, 3, 0, -3, 0, 0, 5, 1, 5, 3, 0, 3, 0, 0]
list2 = [5, 0, 0, 0, 0, 0, 5, 0, 0, 1, 0, 5, 3, 0, 0, 0, 0, 3, 0, 0, 0, 0, 0, 3, 0, 5, 0, 0, 0, 0, 5, 5, 5, 3, 0, 0, 0, 3, 0, 0, 0, 5, 3, 0, 0, 0, 0, 5, 0, 5, 3, 0, 0, 0, 0]

list1[1] = 3list2[1] = 0,我希望能够找到发生这种情况的所有不同索引。

很抱歉,如果这令人困惑,但我真的不知道怎么说这个。

5 个答案:

答案 0 :(得分:11)

>>> [i for i, v in enumerate(list1) if v>=1 and list2[i]==0]
[1, 2, 4, 14, 18, 27, 39, 48, 52]

答案 1 :(得分:7)

另一种变体:

>>> [i for i, (l1, l2) in enumerate(zip(list1, list2)) if l1 >= 1 and l2 == 0]
[1, 2, 4, 14, 18, 27, 39, 48, 52]

答案 2 :(得分:4)

>>>idx_list = [i for i in range(len(list1)) if list1[i] > 1 and list2[i] == 0]

答案 3 :(得分:2)

我发现这更具可读性。

>>> from itertools import count
>>> [i for i,one,two in zip(count(0), list1, list2) if one >= 1 and two == 0]
[1, 2, 4, 14, 18, 27, 39, 48, 52]

这是itertools.count doc

答案 4 :(得分:2)

使用NumPy数组,可以使用逻辑索引:

 import numpy as np
 list1 = np.array([1, -1, 0, 0, 1])
 list2 = np.array([0, 5, 0, 0, 0])

 # Option 1, multiply the logicals together.
 inds = np.where( (list1 >= 1)*(list2 == 0) )[0]

 # Option 2, pure logicals.
 inds = np.where( (list1 >= 1) & (list2 == 0) )[0]

现在inds[0] = 0inds[1] = 4