Python: List merging method

Question

I have a question:

I have 2 lists:

list_1 = [1, 2, 3]
list_2 = [4, 5, 6]

And I want to merge them in order to have the following result:

mergedlist = [1, 4, 2, 5, 3, 6]

How can I do that?

score 2 · Accepted Answer · answered Nov 13 '17 at 13:32

2

Like this:

mergedlist = list_1 + list_2

If you want that specific order in mergedlist:

mergedlist = []
for i, entry in enumerate(list_1):
    mergedlist.extend([entry, list_2[i]])

answered Nov 13 '17 at 13:32

rodgdor

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That's a good iterative way, check my answer if you like to see another solut. Plus one btw – developer_hatch Nov 13 '17 at 13:44

score 0 · Answer 2 · answered Nov 13 '17 at 13:43

0

You can use chain from iter tools:

list_1 = [1, 2, 3]
list_2 = [4, 5, 6]

from itertools import chain

res = list(chain.from_iterable((list_1[x], list_2[x]) for x in range(len(list_1))))

=> [1, 4, 2, 5, 3, 6]

answered Nov 13 '17 at 13:43

developer_hatch

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`zip(list_1, list_2)` works as well – Wondercricket Nov 13 '17 at 13:44
@Wondercricket haha suuuuuure, why I didn't think about that??? so simple... you should post it as answer – developer_hatch Nov 13 '17 at 13:45
Because Kshitij Saraogi beat me to it :) – Wondercricket Nov 13 '17 at 13:47

score 0 · Answer 3 · answered Nov 13 '17 at 13:44

0

In my opinion, the most Pythonic way would be:

merged_list = [item for pair in zip(list_1, list_2) for item in pair]

Alternatively, you can use collections.chain as well:

merged_list = list(chain.from_iterable(zip(list_1, list_2)))

answered Nov 13 '17 at 13:44

Kshitij Saraogi

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Python: List merging method

3 Answers3