regex doubts

[MRAB]

On Jul 19, 10:44 pm, John Machin <sjmac... at lexicon.net> wrote:
> On Jul 20, 6:35 am, MRAB <goo... at mrabarnett.plus.com> wrote:
>
>
>
> > On Jul 19, 9:12 pm, John Machin <sjmac... at lexicon.net> wrote:
>
> > > On Jul 20, 5:04 am, Fredrik Lundh <fred... at pythonware.com> wrote:
>
> > > > Mr SZ wrote:
> > > > > I am taking a string as an input from the user and it should only
> > > > > contain the chars:L , M or R
>
> > > > > I tried the folllowing in kodos but they are still not perfect:
>
> > > > > [^A-K,^N-Q,^S-Z,^0-9]
> > > > > [L][M][R]
> > > > > [LRM]?L?[LRM]? etc but they do not exactly meet what I need.
>
> > > > > For eg: LRLRLRLRLM is ok but LRLRLRNL is not as it has 'N' .like that.
>
> > > > try "[LRM]+$" (an L or an R or an M, one or more times, all the way to
> > > > the end of the string).
>
> > > Ummm ... with the default flag settings, shouldn't that be \Z instead
> > > of $
> > > ?
>
> > $ means end of string unless the multiline flag is used, in which case
> > it means end of line.
>
> What manual are you quoting that from? What version of Python are you
> using? Can you demonstrate that the pattern "[LRM]+$" will fail to
> match the string "L\n"?
>
I see what you mean: $ does match end of line if the newline is the
last character of the string.