how to split an element in python by keeping the separator

Question

hi how can I split this string while keeping '(':

s = ' playsound3Dwhenpossible(soundspotpoint18, %$videos_sounds_path%/sounds/lavazza_-_auguri_cherubini__15_.mp3, true, false, -52.644483, 0.947368, 90, 1, spotpoint18);'
x = s.split("(")
print(x)

I also tried with:

x = s.split("?=(")

but it did not work.

thank you

What does 'keeping the separator' means in your case? The separator as a separate element of the resulting list or joined to one of the adjacent elements? — zwer, Apr 24 '18 at 09:49
Well why do you want to keep separators? If you extract information from string usingg regular expression and group to extract them. — Sumit Jha, Apr 24 '18 at 10:17

score 0 · Answer 1 · answered Apr 24 '18 at 10:00

If you just need to keep the separator, you can re-introduce it after the split:

def split_keep_separator(source, sep):
    elements = source.split(sep)
    return [e for t in zip(elements, [sep] * (len(elements))) for e in t][:-1]

And to test it:

s = ' playsound3Dwhenpossible(soundspotpoint18, %$videos_sounds_path%/sounds/lavazza_-_auguri_cherubini__15_.mp3, true, false, -52.644483, 0.947368, 90, 1, spotpoint18);'

x = split_keep_separator(s, "(")
print(x)

# [' playsound3Dwhenpossible',
#  '(',
#  'soundspotpoint18, %$videos_sounds_path%/sounds/lavazza_-_auguri_cherubini__15_.mp3, true, false, -52.644483, 0.947368, 90, 1, spotpoint18);']

score 0 · Accepted Answer · answered Apr 24 '18 at 10:11

If you want to keep the separator '(' in the output array, the simplest is to use a regex split.

import re
s = ' playsound3Dwhenpossible(soundspotpoint18, %$videos_sounds_path%/sounds/lavazza_-_auguri_cherubini__15_.mp3, true, false, -52.644483, 0.947368, 90, 1, spotpoint18);'
x = re.split(r'(\()', s)

score 0 · Answer 3 · answered Apr 24 '18 at 10:16

Based on your input string, It seems your expected output may be,

[' playsound3Dwhenpossible', '(soundspotpoint18, %$videos_sounds_path%/sounds/lavazza_-_auguri_cherubini__15_.mp3, true, false, -52.644483, 0.947368, 90, 1, spotpoint18);']

If so, this seems easiest to me

s = ' playsound3Dwhenpossible(soundspotpoint18, %$videos_sounds_path%/sounds/lavazza_-_auguri_cherubini__15_.mp3, true, false, -52.644483, 0.947368, 90, 1, spotpoint18);'
print s.replace("(","*(").split('*')

First replace and than split.

Instead of '*', you can use whatever, which is NOT in the original string.

jdehesa · Answer 4 · 2018-04-24T10:28:17.477

Another regex-based solution:

import re

s = ' playsound3Dwhenpossible(soundspotpoint18, %$videos_sounds_path%/sounds/lavazza_-_auguri_cherubini__15_.mp3, true, false, -52.644483, 0.947368, 90, 1, spotpoint18);'
splits = re.findall(r'(\(?[^(]+)', s)
print(splits)

Output:

[' playsound3Dwhenpossible', '(soundspotpoint18, %$videos_sounds_path%/sounds/lavazza_-_auguri_cherubini__15_.mp3, true, false, -52.644483, 0.947368, 90, 1, spotpoint18);']

Or if you want to have a generic (or easy to use) function:

split_keep = lambda s, sep : re.findall('({0}?[^{0}]+)'.format(re.escape(sep)), s)
splits = split_keep(s, '(')

This fails in the corner case of having multiple contiguous separators. The following slightly more complex function fixes it:

split_keep = lambda s, sep : re.findall('({0}[^{0}]*|{0}?[^{0}]+)'.format(re.escape(sep)), s)
print(split_keep('((asda((asfasf', '('))

Output:

['(', '(asda', '(', '(asfasf']

score 0 · Answer 5 · answered Apr 24 '18 at 10:45

You could possibly change your split slightly to :

s = ' playsound3Dwhenpossible(soundspotpoint18, %$videos_sounds_path%/sounds/lavazza_-_auguri_cherubini__15_.mp3, true, false, -52.644483, 0.947368, 90, 1, spotpoint18);'

x = s.split(r'\(') #raw
print(x)

Output:

[' playsound3Dwhenpossible(soundspotpoint18, %$videos_sounds_path%/sounds/lavazza_-_auguri_cherubini__15_.mp3, true, false, -52.644483, 0.947368, 90, 1, spotpoint18);']

how to split an element in python by keeping the separator

5 Answers5