[Python-Dev] file()

[Guido van Rossum]

No, because ValueError is the better exception for an invalid mode string.

On 6/12/06, Georg Brandl <g.brandl at gmx.net> wrote:
> Guido van Rossum wrote:
> > On 6/12/06, Georg Brandl <g.brandl at gmx.net> wrote:
> >> Guido van Rossum wrote:
> >> > Yup, although it's a change in behavior that would need to be studied
> >> > carefully for backwards incompatibilities. Usually it's given as a
> >> > constant, so there won't be any problems; but there might be code that
> >> > receives a mode string and attempts to test its validity by trying it
> >> > and catching IOError, such code would have to be changed.
> >> >
> >> > --Guido
> >> >
> >> > On 6/12/06, Kristján V. Jónsson <kristjan at ccpgames.com> wrote:
> >> >> I notice that file() throws an IOError when it detects an invalid mode
> >> >> string.  Wouldn't a ValueError be more appropriate?
> >> >
> >>
> >> The situation is even more complex with the current trunk. open() raises
> >> ValueError if it detects an invalid the mode string, such as universal
> >> newline mode and a writable mode combined (the definition of
> >> what is invalid has been made stricter, the mode string now must begin
> >> with r, w, a or U), but it raises IOError if the OS call to fopen() fails
> >> because of an invalid mode string. This might need unification.
> >
> > That would be hard to fix unless we get rid of the stdio-based
> > implementation (which I intend to do in Py3k). I say we leave it alone
> > for now -- fopen() can fail for any number of platform-dependent
> > reasons and we can't really expect to do look-before-you-leap on this.
>
> One option would be to raise IOError in the former case too. That's what
> I meant with "unification".
>
> Cheers,
> Georg
>
> _______________________________________________
> Python-Dev mailing list
> Python-Dev at python.org
> http://mail.python.org/mailman/listinfo/python-dev
> Unsubscribe: http://mail.python.org/mailman/options/python-dev/guido%40python.org
>


-- 
--Guido van Rossum (home page: http://www.python.org/~guido/)