Referencing the ith element of each list in a 2d list

Question

Take a 2d list. I want to make a new list with only the ith element from each list. What is the best way to do this?

I have:

 map(lambda x: x[i], l)

Here is an example

 >>> i = 0
 >>> l = [[1,10],[2,20],[3,30]]
 >>> map(lambda x: x[i], l)
 [1, 2, 3]

score 5 · Accepted Answer · edited May 23 '17 at 11:47

5

i = 1
data = [[1,10],[2,20],[3,30]]
result = [d[i] for d in data]  # [10, 20, 30]

Also see this question on list comprehension vs. map.

edited May 23 '17 at 11:47

Community

answered May 05 '11 at 00:16

FMc

or to fit into the original question `result = [x[i] for x in l]` – James Khoury May 05 '11 at 00:17
FYI A list comprehension is more highly optimized than map. – jathanism May 05 '11 at 00:51

1 Answers1