[Python-ideas] FInd first tuple argument for str.find and str.index

Terry Jones terry at jon.es
Wed Sep 5 19:01:23 CEST 2007

>>>>> "Mathias" == Mathias Panzenböck <grosser.meister.morti at gmx.net> writes:
Mathias> I would expect such a method to return the index where one of the
Mathias> given strings was found. Or maybe a tuple: (start, end) or a
Mathias> tuple: (start, searchstring).

It could do something like that if you passed an argument telling it to
quit on the first match. But that makes the return type depend on the
passed arg, which I guess is not good. We'd already be doing that if we
returned a dict, but this would return either a tuple or a dict.

You could drop the dict idea altogether, but you need to consider what to
do if many (probably different) patterns match, all starting at the same
location in the string. For this reason alone I don't think returning a
(start searchstring) tuple is sufficient.

Given that Aho & Corasick find everything you could want to know (all
matches of all patterns), and that they do it in linear time, it doesn't
seem right to throw this information away - especially after going to the
trouble of building and walking the trie.


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