Paul McGuire wrote: > "Fredrik Lundh" <[EMAIL PROTECTED]> wrote in message > news:[EMAIL PROTECTED] > > "Rainy" <[EMAIL PROTECTED]> 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? -- http://mail.python.org/mailman/listinfo/python-list
