regex - Translate perl split to python split -

regex - Translate perl split to python split -

in perl:

split(/(?<=[kr])/,$mystring)

splits mystring after every k or r via 2 concepts "split between every character" (=empty string) + "lookbehind". sequence aaakbbbbr becomes (aaak,bbbbr).

whats counterpart in python? cant find way because empty string not split between characters!

do need around? regular look should [^kr]*[kr]:

in [1]: import re # import regex library in [2]: s = "aaakbbbbr" # define input string in [3]: re.findall(r'[^kr]*[kr]', s) # find matches in string out[3]: ['aaak', 'bbbbr']

regexplanation:

[^kr] # ^ in character classes negation match character except k/r * # quantifier used match 0 or more of previous look [kr] # simple character class matching k/r

in words: match 0 or more characters not k/r followed k/r.

you might want utilize + quantifier match @ to the lowest degree 1 or more instead of * cases like:

in [1]: import re in [2]: s = "kaaakbbbbr" in [3]: re.findall(r'[^kr]*[kr]', s) out[3]: ['k', 'aaak', 'bbbbr'] in [4]: re.findall(r'[^kr]+[kr]', s) out[4]: ['aaak', 'bbbbr']

to create trailing [kr] optional can utilize ?:

in [5]: s = 'aaakbbbbraaa' in [6]: re.findall(r'[^kr]+[kr]?', s) out[6]: ['aaak', 'bbbbr', 'aaa']

python regex perl