regex help for a newbie

[Tobiah]

> 
> I have the following string in my program:
> 
>   string= "aaa%(BBB%(CCC)BBB)aaa%(DDD)aaa"
> 
> Now I need to extract the parts that are enclosed in %().


#!/usr/bin/python

### I realize that this will not serve you in all of the cases
### that you are likely to need to handle, but just to show
### that the case that you mention can be handled with regular
### expressions, I submit the following:

import re

string = "aaa%(BBB%(CCC)BBB)aaa%(DDD)aaa"

m = re.search('([^%]*)%\(([^%]*)%\(([^)]*)\)([^)]*)\)([^)]+)%\(([^)]*)\)(.*)', string)

print (m.groups())


### This yields:
###
### ('aaa', 'BBB', 'CCC', 'BBB', 'aaa', 'DDD', 'aaa')
###
###
###
### Tobiah