Raw strings and escaping

Jon Ribbens jon+usenet at unequivocal.co.uk
Tue Oct 3 14:40:12 CEST 2006


In article <Xns9851834924701duncanbooth at 127.0.0.1>, Duncan Booth wrote:
>> I presume there was originally some reason for this bizarre behaviour
>> - it'd be interesting to know what it is/was, if anyone knows?
>> 
> See the FAQ for the explanation:
> 
> http://www.python.org/doc/faq/general/#why-can-t-raw-strings-r-strings-end-with-a-backslash
> 
> The idea is that if you use raw strings for regular expressions you can 
> write things like:
> 
>   pattern = r'[\'"]'
> 
> if the raw string simply ignored the backslash altogether it would be much 
> harder to write regular expressions that contain both sorts of quotes.

Well, hardly *much* harder:

  pattern = r"""foo"""

Personally, I think that raw strings behaving as they do is
unexpected, unintuitive and unnecessary, but it's obviously too late
to change it now anyway ;-)

I think standard strings accepting backslash followed by an unexpected
character is also a mistake, but again it's too late to fix now.



More information about the Python-list mailing list