[Python-Dev] Unicode filenames

[Just van Rossum]

Walter D=F6rwald wrote:

> Just van Rossum wrote:
>=20
> > [...]
> > BTW. if I try to create a file with an 8-bit filename which is _not_
> > valid utf-8, I get a strange error:
> >=20
> >   >>> f =3D open("\xff", "w")
> >   Traceback (most recent call last):
> >     File "<stdin>", line 1, in ?
> >   IOError: invalid mode: w
> >   >>>=20
> >=20
> > This exception is thrown when errno is EINVAL, which apparently can
> > also mean that the filename arg is bad. Not sure if we can fix this.

> But when the system default encoding (i.e. sys.getdefaultencoding())
> and the file system encoding are different, I'd say the filename has
> to be transcoded from the system default encoding to the filesystem
> encoding before it is used.

In most places (probably all, uness there's a bug)
Py_FileSystemDefaultEncoding only has relevance for unicode strings:
8-bit strings are passed to the underlying calls unaltered. So the above
traceback is the result of the _OS_ refusing to name a file "\xff",
which is natural as this particular OS (OSX) uses UTF-8 as the native
file system encoding and "\xff" is not valid UTF-8. (I was actually
pleasantly surprised the OS actually _cares_ ;-)

Just