[Python-ideas] Proposed convenience functions for re module

[MRAB]

Steven D'Aprano wrote:
> On Thu, 23 Jul 2009 07:38:11 am Mark Dickinson wrote:
> 
>> Steven, could you show some examples of real(ish)-world use-cases
>> for one or both of these functions?  Preferably including the code
>> that might directly follow a multimatch or multisearch call.
> 
> I'm afraid that I don't use regexes anywhere near enough to champion 
> this proposal in the face of serious opposition, or even skepticism. If 
> this isn't a simple enough "no-brainer", then I'm going to have to pass 
> the baton onto somebody else (assuming anyone actually likes this 
> idea).
> 
> This idea came about from the thread started by Sean Reifschneider, 
> proposing adding regexes to strings. I thought (and Sean seemed to 
> agree) that these convenience functions would solve his primary 
> use-case. So this proposal isn't scratching an itch I have.
> 
> 
>> It's probably because I haven't used regexes widely enough, but
>> in all the potential examples I can come up with, either
>>
>> (1) the regexes are similar enough that they can be refactored into
>> a single regex (e.g., just concatenated with '|'), or
>>
>> (2) they're distinct enough that each regex needs its own handing,
>> so that the multimatch/multisearch would need to be followed by
>> a multiway 'if/elif/else' anyway;  in this case, it seems that little
>> is gained.
> 
> These are both reasonable approaches. This proposal isn't supposed to 
> solve every multiple-regex-handling problem.
> 
> So far support for this has been luke-warm. If anyone really likes this 
> idea, please speak up, otherwise I'll let it drop.
> 
If you want to try multiple regexes until one matches then the approach
with re.match accepting a tuple of patterns would, it seems to me, to be
the one that requires the smallest change and has the greatest
precedence (like str.startwith).