[Tutor] Matching with beginning of the line in the character set

[Kent Johnson]

Smith, Jeff wrote:
> Kent,
> 
> I think \b will work for me since I was really looking for [\A\W]
> anyway.
> 
> That still doesn't answer the generalized question about something like
> [\A\d] for instance.

I know :-)

The docs say [] is "Used to indicate a set of characters." So it kind of makes sense that it works 
for \w and \s, which are just shortcuts for sets of characters themselves, but not for \A which is 
something different.

Kent

> 
> Thanks,
> Jeff
> 
> BTW, I was using raw strings although I forgot to put that in.
> 
> -----Original Message-----
> From: Kent Johnson [mailto:kent37 at tds.net] 
> Sent: Tuesday, February 01, 2005 1:15 PM
> Cc: Tutor at python.org
> Subject: Re: [Tutor] Matching with beginning of the line in the
> character set
> 
> 
> 
> 
> Smith, Jeff wrote:
> 
>>I want to match a string which is preceeded by a space or occurs at 
>>the beginning of the line.  I also don't want to catch the preceeding 
>>character as a group.
>>
>>I have found both of the following to work
>>	re.compile('(?:^|\s)string')
>>	re.compile('(?:\A|\s)string')
> 
> 
> How about r'\bstring' ? It doesn't mean quite the same as \sstring but
> it might work for you.
> 
> 
>>But would prefer to use the more concise [] notation.  However
>>	re.compile('[^\s]string')
> 
> 
> As the first character in [], ^ means 'not'.
> 
> 
>>Does not work and
>>	re.compile('[\A\s]string')
> 
> 
> I guess \A doesn't count as a 'character class'? Or do you need to be
> using raw strings?
> 
> Kent
> 
> 
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