[Python-Dev] \G (match last position) regex operator non-existant in python?

Ed Peschko horos22 at gmail.com
Fri Oct 27 02:03:05 EDT 2017


perl has a regex assertion (\G) that allows multiple-match regular
expressions to be able to use the position of the last match. Perl's
documentation puts it this way:

    \G Match only at pos() (e.g. at the end-of-match position of prior m//g)

Anyways, this is exceedingly powerful for matching regularly
structured free-form records, and I was really surprised when I found
out that python did not have it. For example, if findall supported
this, it would be possible to write things like this (a quick and
dirty ifconfig parser):

pat = re.compile(r'\G(\S+)(.*?\n)(?=\S+|\Z)', re.S)

val = """
eth2      Link encap:Ethernet  HWaddr xx
             inet addr: xx.xx.xx.xx  Bcast:xx.xx.xx.xx  Mask:xx.xx.xx.xx
lo        Link encap:Local Loopback
           inet addr:  Mask:
 matches = re.findall(pat, val)

So - why doesn't python have this? is it something that simply was
overlooked, or is there another method of doing the same thing with
arbitrarily complex freeform records?

thanks much..

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