Problem with .next() method adding junk characters.

[Rainy]

Paul McGuire wrote:
> "Fredrik Lundh" <fredrik at pythonware.com> wrote in message
> news:mailman.1076.1159776001.10491.python-list at python.org...
> > "Rainy" <ak at silmarill.org> wrote:
> >
> >> I'm just curious as to what's happening. I understand that you're not
> >> supposed to call .next on a file open for writing. But I don't know why
> >> and how it does what happened here; besides, I've seen the same thing
> >> happen before when I was doing something else with file
> >> open/write/close, but I don't remember the specifics.
> >
> > C's stdio library require you to call "flush" when switching between
> > reading and
> > writing; if you don't, the result is undefined.
> >
> > </F>
> >
>
> Sure enough, following the OP's original sequence, with an intervening flush
> between the writes and next, leaves the file in the expected state:
>
> >>> f = file("xyzzy.dat","w")
> >>> f.write("1\n")
> >>> f.write("2\n")
> >>> f.write("3\n")
> >>> f.flush()
> >>> f.next()
> Traceback (most recent call last):
>   File "<stdin>", line 1, in ?
> IOError: [Errno 9] Bad file descriptor
> >>> f.close()
> >>> f = file("xyzzy.dat")
> >>> f.next()
> '1\n'
> >>> f.next()
> '2\n'
> >>> f.next()
> '3\n'
> >>> f.next()
> Traceback (most recent call last):
>   File "<stdin>", line 1, in ?
> StopIteration
> >>>
>
> I would guess then that the likely extent of any fix to this "bug" would be
> documentation to the effect of Fredrik's last comment above.
> 
> -- Paul

Thanks.. I get it now. Should I close the bug report then?