reusing parts of a string in RE matches?
johnjsal at NOSPAMgmail.com
Wed May 10 21:37:46 CEST 2006
John Salerno wrote:
> mpeters42 at gmail.com wrote:
>>>>> string = 'abababababababab'
>>>>> pat = 'aba'
>>>>> [pat for s in re.compile('(?='+pat+')').findall(string)]
>> ['aba', 'aba', 'aba', 'aba', 'aba', 'aba', 'aba']
> Wow, I have no idea how to read that RE. First off, what does it match?
> Should something come before the parentheses, and that will be what
> matches? Also, what are the '+'s doing? Are they literal +s or still
> being used as RE syntax?
Nevermind, I get it! The point is that you *aren'* matching anything
(except the empty string), and this only to see how many times it
occurs, then you are replacing those occurrences with the pattern
string. So this is basically like a counter?
More information about the Python-list