Which is faster...find or re. ?

Keith Dart kdart at kdart.com
Sat Aug 3 11:49:50 CEST 2002


In article <7d3dc526.0208020948.15403600 at posting.google.com>, "Fearless
Freep" <joconnor at cybermesa.com> penned these words:

> I'm doing some parsing on HTML files and lookfor for particular tags.
> 
> First off given a single line that I want to find a string in, would it
> be quicker to do
> 
> if string.find(line, searchString) > -1:
>     #process line
> 

I did some testing of this a little while ago. The answer is, as usual:
"It depends". If you are doing a simple string match (or find) then
string.find is about ten times faster than a RE. It is almost alwasy
faster. However, if you are doing some kind of parsing, REs are faster
that scanning/chopping/slicking strings in python. The more complex the
string matching and (especially) cutting out bits of strings then REs are
faster. 

HTH,
Keith
 

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