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Simple question - end a raw string with a single backslash ?


For a neatish way to get a string to end with a single backslash, how about
   mystr = r"abc\ "[:-1]
(Note the space at the end of the rough-quoted string.)


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On Mon, Oct 19, 2020 at 9:26 AM Antoon Pardon <antoon.pardon at vub.be> wrote:

>
>
> Op 13/10/20 om 15:14 schreef Serhiy Storchaka:
> > 13.10.20 11:52, Tony Flury via Python-list ????:
> >> I am trying to write a simple expression to build a raw string that ends
> >> in a single backslash. My understanding is that a raw string should
> >> ignore attempts at escaping characters but I get this :
> >>
> >>      >>> a = r'end\'
> >>        File "<stdin>", line 1
> >>          a = r'end\'
> >>                    ^
> >>     SyntaxError: EOL while scanning string literal
> >>
> >> I interpret this as meaning that the \' is actually being interpreted as
> >> a literal quote - is that a bug ?
> >
> > r'You can\'t end raw string literal with a single "\"'
> >
> > If backslash be true inner in a raw string, the above literal would end
> > after \'. It would be very hard to write a raw string containing both \'
> > and \", and even \''' and \""" (there are such strings in the stdlib).
> >
> > So you have problem either with trailing backslash, or with inner
> > backslash followed by quotes. Both problems cannot be solved at the same
> > time. Python parser works as it works because initially it was easier to
> > implement, and now this cannot be changed because it would break some
> > amount of correct code.
>
> IMO the way python does this is broken.
>
>  >>> st=r'You can\'t end raw string literal with a single "\"'
>  >>> print(st)
>
> Now either the \ is special or it is not.
>
> 1) If it is special, it should change how the ' is treated but not
> appear itself.
>
> 2) If it is not special, it should just appear and not change how the '
> is treated.
>
> What python does here is a combination of both. The \ appears and it
> changes how the ' is treated. That is IMO broken.
>
> --
> Antoon Pardon.
> --
> https://mail.python.org/mailman/listinfo/python-list
>