r'\' - python parser bug?

[Fuzzyman]

Duncan Booth <me at privacy.net> wrote in message news:<Xns94F55D228C7AAduncanrcpcouk at 127.0.0.1>...
> michael at foord.net (Fuzzyman) wrote in 
> news:8089854e.0405252339.18e0c59d at posting.google.com:
> 
> >>>> print r'c:\subdir\'
>  SyntaxError: EOL while scanning single-quoted string
> >>>> 
>  
> >> When the parser sees a backslash inside
> >> a string literal, it always skips the next character. 
> > In the above example the parser *only* skips the next character if it
> > is at the end of the string... surely illogical. The reason given is
> > effectively 'raw strings were created for regular expressions, so it
> > doesn't matter if the behaviour is illogical' (and precludes other
> > reasonable uses!!)..........
> > 
> 
> In a python string, backslash is an escape character which gives the next 
> character(s) special meaning, so '\n' is a single newline character. If the 
> escaped character isn't a known escape then the parser simply passes 
> through the entire sequence. So '\s' is a two character string. In all 
> cases at least one character following the backslash is parsed when the 
> backslash is encountered, and this character can never form part of the 
> string terminator.
> 
> Raw strings are processed in exactly the same way as normal strings, except 
> that no escape sequences are recognised, however the character following 
> the backslash is still prevented from terminating the string, just as it 
> would in any other string. This *useful*? behaviour allows you to put 
> single and double quotes into a raw string provided that they are preceded
> by a backslash.
> 
>   print r'c:\subdir\'file'
> 
> Raw strings aren't intended for writing DOS pathnames, they are actually 
> targetted for regular expressions where this behaviour makes more sense.
> 
[snip..]

Yeah.. that's not an annoying feature.... I mean no-one would ever
want to use strings to hold Windows pathnames in......


Regards,

Fuzzy