Large regular expressions

Stefan Behnel stefan_ml at
Mon Mar 15 13:45:31 CET 2010

Nathan Harmston, 15.03.2010 13:21:
> So I m trying to use a very large regular expression, basically I have
> a list of items I want to find in text, its kind of a conjunction of
> two regular expressions and a big list......not pretty. However
> everytime I try to run my code I get this exception:
> OverflowError: regular expression code size limit exceeded
> I understand that there is a Python imposed limit on the size of the
> regular expression. And although its not nice I have a machine with
> 12Gb of RAM just waiting to be used, is there anyway I can alter
> Python to allow big regular expressions?
> Could anyone suggest other methods of these kind of string matching in
> Python?

If what you are trying to match is in fact a set of strings instead of a 
set of regular expressions, you might find this useful:


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