Attached are diffs for the sre.py module and to its
documentation. Testing should also be added.
=========================
My message to python-dev:
Hello,
I've now finished teaching Python to a group of people,
and regular expressions was a part of the course. I
have encountered a few missing features (that is,
optional arguments) in RE functions. I've checked, and
it seems to me that they can be added very easily.
The first missing feature is the "flags" argument in
the findall and finditer functions. Searching for all
occurances of an RE is, of course, a legitimate action,
and I had to use (?s) in my RE, instead of adding
re.DOTALL, which, to my opinion, is a lot clearer.
The solution is simple: the functions sub, subn, split,
findall and finditer all first compile the given RE,
with the flags argument set to 0, and then run the
appropriate method. As far as I can see, they could all
get an additional optional argument, flags=0, and
compile the RE with it.
The second missing feature is the ability to specify
start and end indices when doing matches and searches.
This feature is available when using a compiled RE, but
isn't mentioned at all in any of the straightforward
functions (That's why I didn't even know it was
possible, until I now checked - I naturally assumed
that all the functionality is availabe when using the
functions).
I think these should be added to the functions match,
search, findall and finditer. This feature isn't
documented for the findall and finditer methods, but I
checked, and it seems to work fine.
(In case you are interested in the use case: the
exercise was to parse an XML file. It was done by first
matching the beginning of a tag, then trying to match
attributes, and so on - each match starts from where
the previous successfull match ended. Since I didn't
know of this feature, it was done by replacing the
original string with a substring after every match,
which is terribly unefficient.)
|
➜
