Wednesday, December 5, 2018

Match a line with multiple regex using Python

You can use the built in functions any (or all if all regexes have to match) and a Generator expression to cicle through all the regex-objects.


any (regex.match(line) for regex in [regex1, regex2, regex3])


(or any(re.match(regex_str, line) for regex in [regex_str1, regex_str2, regex_str2]) if the regexes are not pre-compiled regex objects, of course)


Although that will be ineficient compared to combining your regexes in a single expression - if this code is time or cpu critical, you should try instead, composing a single regular expression that encompass all your needs, using the special | regex operator to separate the original expressions.
A simple way to combine all the regexs is to use the string "join" operator:


re.match("|".join([regex_str1, regex_str2, regex_str2]) , line)


Although combining the regexes on this form can result in wrong expressions if the original ones already do make use of the | operator.

No comments:

Post a Comment

plot explanation - Why did Peaches' mom hang on the tree? - Movies & TV

In the middle of the movie Ice Age: Continental Drift Peaches' mom asked Peaches to go to sleep. Then, she hung on the tree. This parti...