python - splitting a string without removing delimiters

Question

I'm trying to split a string without removing the delimiter and having trouble doing so. The string I want to split is:

'+ {- 9 4} {+ 3 2}'

and I want to end up with

['+', '{- 9 4}', '{+ 3 2}']

yet everything I've tried hasn't worked. I was looking through this stackoverflow post for answers as well as google: Python split() without removing the delimiter

Thanks!

Answer 1

re.split will keep the delimiters when they are captured, i.e., enclosed in parentheses:

import re
s = '+ {- 9 4} {+ 3 2}'
p = filter(lambda x: x.strip() != '', re.split("([+{} -])", s)) 

will give you

['+', '{', '-', '9', '4', '}', '{', '+', '3', '2', '}']

which, IMO, is what you need to handle nested expressions