regex help: splitting string gets weird groups
python.list at tim.thechases.com
Thu Apr 8 22:02:22 CEST 2010
> [ python3.1.1, re.__version__='2.2.1' ]
> I'm trying to use re to split a string into (any number of) pieces of
> these kinds:
> 1) contiguous runs of letters
> 2) contiguous runs of digits
> 3) single other characters
> e.g. 555tHe-rain.in#=1234 should give: [555, 'tHe', '-', 'rain',
> '.', 'in', '#', '=', 1234]
> I tried:
>>>> re.match('^(([A-Za-z]+)|([0-9]+)|([-.#=]))+$', '555tHe-rain.in#=1234').groups()
> ('1234', 'in', '1234', '=')
> Why is 1234 repeated in two groups? and why doesn't "tHe" appear as a
> group? Is my regexp illegal somehow and confusing the engine?
well, I'm not sure what it thinks its finding but nested capture-groups
always produce somewhat weird results for me (I suspect that's what's
triggering the duplication). Additionally, you're only searching for
one match (.match() returns a single match-object or None; not all
possible matches within the repeated super-group).
> I *would* like to understand what's wrong with this regex, though if
> someone has a neat other way to do the above task, I'm also interested
> in suggestions.
Tweaking your original, I used
>>> import re
['555', 'tHe', '-', 'rain', '.', 'in', '#', '=', '1234']
The only difference between my results and your results is that the 555
and 1234 come back as strings, not ints.
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