Another re question

[Kent Polk]

On 24 Oct 2000 14:36:21 -0400, Andrew Kuchling wrote:
>kent at tiamat.goathill.org (Kent Polk) writes:
>>  >>> findpid_pat = r'\012+\d |0*\w*[\t, ]+([\w ]+)'
>> I don't understand how a empty string matches in this last
>>case. Separately they are:
>> 
>>  >>> findpid_pat = r'\012+\d *\w*[\t, ]+([\w ]+)'
>>  >>> findpid_pat = r'\012+0*\w*[\t, ]+([\w ]+)'
>
>Oh no they're not; they're '\d ' and '0*\w*[\t, ]+([\w ]+)'.
>'|' has lower precedence than concatenation, so everything after the |
>is in the second branch.
>Try:
>findpid_pat = r'\012+(?:\d |0*)\w*[\t, ]+([\w ]+)'

So *that's* what 'A non-grouping version of regular parentheses'
means. :^) That's exactly what I was trying to do but got confused
with the syntax and figured it was a wild goose chase.

Thanks So Much!

>(How I caught this: by uncommenting the p.dump() commend in
>Lib/sre_parse.py.  It would be nice to have a way to request a dump of
>the bytecode for an SRE pattern.)

and for this hint.