[Python-Dev] Experiment: Adding "re" to string objects.

[Sean Reifschneider]

I'm mailing this to python-dev because I'd like feedback on the idea of
adding an "re" attribute to strings.  I'm not sure if it's a good idea or
not yet, but I figure it's worth discussion.  The module mentioned here
includes a class called "restr()" which allows you to play with "s.re".

As some of you may recall, I'm not particularly fond of the recipe:

   m = re.match(r'whatever(.*)', s)
   if m:
      m.group(1)

The other morning I came up on the idea of adding an "re" to strings, so
you could do things like:

   if s.re.match(r'whatever(.*)'):
      print s.re.group(1)

or:

   if (date.re.match(r'(?P<year>\d\d\d\d)-(?P<month>\d\d)' or
         date.re.match(r'(?P<month>\d\d)-(?P<year>\d\d\d\d)'):
      print date.re.groupdict('year')

So I decided to try experimenting with it and see how I like it.  I've also
thrown a bunch of other stuff into it and made a module called
"filtertools":

   http://pypi.python.org/pypi/filtertools/0.01
   ftp://ftp.tummy.com/pub/tummy/Python/python-filtertools/

As the version number is meant to indicate, this is something that I'm
still exploring whether it is the right thing done in the right way.
Though at the moment the only thing I plan to change is that some of the
iterators (having nothing to do with adding "re" to string objects)
probably shouldn't consume the "barrier" such as the "dropwhile()" and
"takewhile()".  You might want to do something like:

   fp = filtertools.reopen('mailbox')
   for header in filtertools.takewhile([ r'^\S' ], fp.readlines()) :
      print 'HEADER:', header.rstrip()
      for continued in filtertools.takewhile([ r'^\s+\S' ], fp.readlines()) :
         print 'CONTINUED:', continued.rstrip()

But, the "takewhile()" I will consume the first non-matching line.

Anyway, I appreciate any feedback folks have.

Thanks,
Sean
-- 
 What we see depends on mainly what we look for.
                 -- John Lubbock
Sean Reifschneider, Member of Technical Staff <jafo at tummy.com>
tummy.com, ltd. - Linux Consulting since 1995: Ask me about High Availability