CODEWITHSUNDEEP
pythonregex
fghoussen
fghoussen

Reputation: 565

Python - how to split a string using regex but preserving pattern that contains the split separator?

Starting from "param1=1-param2=1.e-01-param3=A", how to get
["param1=1", "param2=1.e-01", "param3=A"] ? The problem is that the separator "-" may be contained in the value of a parameter.

Franck

>>> import re
>>> re.split("-", "param1=1-param2=1.e-01-param3=A")
['param1=1', 'param2=1.e', '01', 'param3=A']
>>> re.split("[^e]-[^0]", "param1=1-param2=1.e-01-param3=A")
['param1=', 'aram2=1.e-0', 'aram3=A']
>>> re.split("[?^e]-[?^0]", "param1=1-param2=1.e-01-param3=A")
['param1=1-param2=1.', '1-param3=A']

EDIT

OK, I forgot to mention param1, param2, param3 do actually not share the same "param" string. What about if we have to split "p=1-q=1.e-01-r=A"into the same kind of list ["p=1", "q=1.e-01", "r=A"] ?

EDIT

>>> re.split("(?:-)(?=[a-z]+)", "p=1-q=1.e-01-r=A")
['p=1', 'q=1.e-01', 'r=A']

Does the job for me as I know parameter names can not carry any -.

Thanks, guys !

Upvotes: 2

Views: 69

Answers (2)

Ajay2588
Ajay2588

Reputation: 567

For other strings,

Try out this https://regex101.com/r/zwI2Mk/1 and https://regex101.com/r/zwI2Mk/1/codegen?language=python

Upvotes: 0

DeepSpace
DeepSpace

Reputation: 81684

By using non-capturing group and positive lookahead, capture '-' only if it is followed by 'param':

import re

string = "param1=1-param2=1.e-01-param3=A"
print(re.split(r"(?:-)(?=param)", string))
# ['param1=1', 'param2=1.e-01', 'param3=A']

Live demo on regex101

Upvotes: 2

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