There doesn't seem to be any reasonable way to search
a string backwards for a regular expression, starting
from a given character position. I notice that the
underlying C regular expression implemention supports
a direction flag.

I propose adding a direction flag to the search function
on match objects:

r = re.compile(...)
m = re.search(str, startpos=5000, endpos=-1, dir=-1)

would search in str for r, starting at
location 5000 and searching backwards through
location 0 (the beginning of the string).

This is useful in (for example) text editors where
you want to be able to search forwards or backwards,
or if you're parsing an html file and see a </table>
and want to find the matching <table>, etc.

phr

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Moved to feature requests tracker.

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Another way to do this would be add a direction flag to the
regexp itself, like re.R (for reverse) if R isn't already in use:

   group  = re.search(pat, str, start, end, re.R)

or something like that.

I continue to want this feature. It's very handy for writing
web scrapers, which I do fairly frequently.

Does this request still stand? I'm working on the re module at the moment.

Why not? I needed such a feature some time ago.
But if possible, it should be a keyword argument:
re.search(..., backwards=True)
similar to list.sort(reverse=True)

Implemented as part of bpo-3825.

Hello, I wanted to use this feature and found this issue. It is marked as closed, being a duplicate of another closed issue. However the feature is actually not present. In 2008 it was planned to be added by Matthew Barnett in bpo-3825, but the work of improving re module moved to bigger project under bpo-2636 which resulted in regex package to be evenually included in stdlib. So unless regex is included in stdlib, one should try regex package (e.g. pip install regex).

I've put here this summary just in case there is someone like me who looked for the feature and found this issue.