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Re: Question about metacharacter '*'

From Roy Smith <roy@panix.com>
Newsgroups comp.lang.python
Subject Re: Question about metacharacter '*'
Date 2014-07-06 12:47 -0400
Organization PANIX Public Access Internet and UNIX, NYC
Message-ID <roy-279E10.12473806072014@news.panix.com> (permalink)
References <3f7ecf04-b881-4e79-aa59-893580090468@googlegroups.com> <CABicbJKUOsKW77LGkDF-1E52AmsPpTJq=GAUTA2PLpff+7fxNQ@mail.gmail.com> <53B96C0A.3030302@mrabarnett.plus.com> <mailman.11545.1404662273.18130.python-list@python.org> <d8f8d76d-0a47-4f59-8f09-da2a44cc1d2e@googlegroups.com>

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In article <d8f8d76d-0a47-4f59-8f09-da2a44cc1d2e@googlegroups.com>,
 Rick Johnson <rantingrickjohnson@gmail.com> wrote:

> As an aside i prefer to only utilize a "character set" when
> nothing else will suffice. And in this case r"[0-9][0-9]*"
> can be expressed just as correctly  (and less noisy IMHO) as
> r"\d\d*".

Even better, r"\d+"

>>> re.search(r'(\d\d*)', '111aaa222').groups()
('111',)
>>> re.search(r'(\d+)', '111aaa222').groups()
('111',)

Oddly enough, I prefer character sets to the backslash notation, but I 
suppose that's largely because when I first learned regexes, that 
new-fangled backslash stuff hadn't been invented yet. :-)

I know I've said this before, but people should put more effort into 
learning regex.  There are lots of good tools in Python (startswith, 
endswith, split, in, etc) which handle many of the most common regex use 
cases.  Regex is also not as easy to use in Python as it is in a 
language like Perl where it's baked into the syntax.  As a result, 
pythonistas tend to shy away from regex, and either never learn the full 
power, or let their skills grow rusty.  Which is a shame, because for 
many tasks, there's no better tool.

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Thread

Question about metacharacter '*' rxjwg98@gmail.com - 2014-07-06 04:51 -0700
  Re: Question about metacharacter '*' Devin Jeanpierre <jeanpierreda@gmail.com> - 2014-07-06 05:09 -0700
    Re: Question about metacharacter '*' rxjwg98@gmail.com - 2014-07-07 11:51 -0700
      Re: Question about metacharacter '*' Devin Jeanpierre <jeanpierreda@gmail.com> - 2014-07-07 13:27 -0700
      Re: Question about metacharacter '*' Mark Lawrence <breamoreboy@yahoo.co.uk> - 2014-07-07 22:50 +0100
  Re: Question about metacharacter '*' MRAB <python@mrabarnett.plus.com> - 2014-07-06 16:32 +0100
  Re: Question about metacharacter '*' Devin Jeanpierre <jeanpierreda@gmail.com> - 2014-07-06 08:50 -0700
    Re: Question about metacharacter '*' Rick Johnson <rantingrickjohnson@gmail.com> - 2014-07-06 09:24 -0700
      Re: Question about metacharacter '*' Rick Johnson <rantingrickjohnson@gmail.com> - 2014-07-06 09:32 -0700
      Re: Question about metacharacter '*' Roy Smith <roy@panix.com> - 2014-07-06 12:47 -0400
        Re: Question about metacharacter '*' Rick Johnson <rantingrickjohnson@gmail.com> - 2014-07-06 10:38 -0700
          Re: Question about metacharacter '*' Rick Johnson <rantingrickjohnson@gmail.com> - 2014-07-06 10:58 -0700

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