How to convert a string of space- and comma- separated numbers into a list of int?

Question

I have a string of numbers, something like:

example_string = '0, 0, 0, 11, 0, 0, 0, 0, 0, 19, 0, 9, 0, 0, 0, 0, 0, 0, 11'

I would like to convert this into a list:

example_list = [0, 0, 0, 11, 0, 0, 0, 0, 0, 19, 0, 9, 0, 0, 0, 0, 0, 0, 11]

I tried something like:

for i in example_string:
    example_list.append(int(example_string[i]))

But this obviously does not work, as the string contains spaces and commas. However, removing them is not an option, as numbers like '19' would be converted to 1 and 9. Could you please help me with this?

`example_string.split(',')` – Jochen Ritzel Oct 12 '13 at 12:52 — Jochen Ritzel, Oct 12 '13 at 12:52

Martijn Pieters · Accepted Answer · 2020-09-26T17:00:54.383

91

Split on commas, then map to integers:

map(int, example_string.split(','))

Or use a list comprehension:

[int(s) for s in example_string.split(',')]

The latter works better if you want a list result, or you can wrap the map() call in list().

This works because int() tolerates whitespace:

>>> example_string = '0, 0, 0, 11, 0, 0, 0, 0, 0, 19, 0, 9, 0, 0, 0, 0, 0, 0, 11'
>>> list(map(int, example_string.split(',')))  # Python 3, in Python 2 the list() call is redundant
[0, 0, 0, 11, 0, 0, 0, 0, 0, 19, 0, 9, 0, 0, 0, 0, 0, 0, 11]
>>> [int(s) for s in example_string.split(',')]
[0, 0, 0, 11, 0, 0, 0, 0, 0, 19, 0, 9, 0, 0, 0, 0, 0, 0, 11]

Splitting on just a comma also is more tolerant of variable input; it doesn't matter if 0, 1 or 10 spaces are used between values.

edited Sep 26 '20 at 17:00

answered Oct 12 '13 at 12:52

Martijn Pieters

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For the python3, you have to change `map(int, example_string.split(','))` to `list(map(int, example_string.split(',')))`. – Tengerye Sep 13 '18 at 01:11
1

@Tengerye: that depends; if you only need an iterable the `map()` object is fine as it is. – Martijn Pieters Sep 13 '18 at 08:34
Thanks a million!!!! – Emjey Dec 05 '19 at 18:14

score 12 · Answer 2 · answered Oct 12 '13 at 12:55

12

I guess the dirtiest solution is this:

list(eval('0, 0, 0, 11, 0, 0, 0, 11'))

answered Oct 12 '13 at 12:55

hendrik

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If the original string of numbers was stored in "python format", this solution will actually adapt to whatever type of data is stored. '0, 0, 0, 11' will map to int type and '0.12, 0.1, 1.2' will map to float type without having to explicitly code for it. – Marcos Nov 10 '16 at 07:56
3

It could be dirtier, but it's dirty enough to earn you my downvote. Why even post a horrible solution like that? – Aran-Fey Jun 03 '18 at 07:09

score 7 · Answer 3 · answered Oct 12 '13 at 12:53

7

it should work

example_string = '0, 0, 0, 11, 0, 0, 0, 0, 0, 19, 0, 9, 0, 0, 0, 0, 0, 0, 11'
example_list = [int(k) for k in example_string.split(',')]

answered Oct 12 '13 at 12:53

lucemia

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score 7 · Answer 4 · edited Oct 08 '14 at 15:49

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number_string = '0, 0, 0, 11, 0, 0, 0, 0, 0, 19, 0, 9, 0, 0, 0, 0, 0, 0, 11'

number_string = number_string.split(',')

number_string = [int(i) for i in number_string]

edited Oct 08 '14 at 15:49

Edd

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answered Oct 08 '14 at 15:12

Rohit Singh

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Hey Rohit :). Welcome to SO. Do you mind adding a bit explanations to your code? So the next guys coming in have a better idea of what you're doing with your answer :). – Patrice Oct 08 '14 at 15:17

score 6 · Answer 5 · answered Oct 12 '13 at 12:53

6

You can also use list comprehension on splitted string

[ int(x) for x in example_string.split(',') ]

answered Oct 12 '13 at 12:53

lejlot

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score 2 · Answer 6 · answered Oct 12 '13 at 12:54

2

Try this :

import re
[int(s) for s in re.split('[\s,]+',example_string)]

answered Oct 12 '13 at 12:54

Charles JOUBERT

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How to convert a string of space- and comma- separated numbers into a list of int?

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