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Re: re Questions

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On 26/01/2014 17:25, Chris Angelico wrote:
> On Mon, Jan 27, 2014 at 4:15 AM, Roy Smith <roy@panix.com> wrote:
>> In article <mailman.5996.1390756093.18130.python-list@python.org>,
>>   Chris Angelico <rosuav@gmail.com> wrote:
>>
>>> The set [A-z] is equivalent to
>>> [ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`abcdefghijklmnopqrstuvwxyz]
>>
>> I'm inclined to suggest the regex compiler should issue a warning for
>> this.
>>
>> I've never seen a character range other than A-Z, a-z, or 0-9.  Well, I
>> suppose A-F or a-f if you're trying to match hex digits (and some
>> variations on that for octal).  But, I can't imagine any example where
>> somebody wrote A-z and it wasn't an error.
>
> I've used a variety of character ranges, certainly more than the 4-5
> you listed, but I agree that A-z is extremely likely to be an error.
> However, I've sometimes used a regex (bytes mode) to find, say, all
> the ASCII printable characters - [ -~] - and I wouldn't want that
> precluded. It's a bit tricky trying to figure out which are likely to
> be errors and which are not, so I'd be inclined to keep things as they
> are. No warnings.
>
> ChrisA
>

I suggest a single warning is always given "Regular expressions can be 
fickle.  Have you considered using string methods?".  My apologies to 
regex fans if they're currently choking over their tea, coffee, cocoa, 
beer, scotch, saki, ouzo or whatever :)

-- 
My fellow Pythonistas, ask not what our language can do for you, ask 
what you can do for our language.

Mark Lawrence

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re Questions Blake Adams <blakesadams@gmail.com> - 2014-01-26 08:59 -0800
  Re: re Questions Larry Martell <larry.martell@gmail.com> - 2014-01-26 10:06 -0700
    Re: re Questions Blake Adams <blakesadams@gmail.com> - 2014-01-26 09:15 -0800
  Re: re Questions Chris Angelico <rosuav@gmail.com> - 2014-01-27 04:08 +1100
    Re: re Questions Roy Smith <roy@panix.com> - 2014-01-26 12:15 -0500
      Re: re Questions Chris Angelico <rosuav@gmail.com> - 2014-01-27 04:25 +1100
      Re: re Questions Mark Lawrence <breamoreboy@yahoo.co.uk> - 2014-01-26 17:39 +0000
      Re: re Questions Tim Chase <python.list@tim.thechases.com> - 2014-01-26 13:41 -0600
    Re: re Questions Blake Adams <blakesadams@gmail.com> - 2014-01-26 09:15 -0800
      Re: re Questions Mark Lawrence <breamoreboy@yahoo.co.uk> - 2014-01-26 17:30 +0000

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