[Python-3000] [Python-Dev] Filename as byte string in python 2.6 or 3.0?

[Terry Reedy]

Glenn Linderman wrote:

> My understanding of the Posix file names is that any byte values are 
> valid except "/" and null.  Is this a correct understanding?
> 
> The UTF-8b proposal seems to translate from a non-UTF-8 byte stream to a 
> Unicode character stream.  Call the original byte stream FOO.  The 
> transformation then produces FOOTR, a set of Unicode code points.  Now 
> FOOTR has a representation in UTF-8, which is a byte stream, call that 
> byte stream FOOTRUTF8.  How, by looking at FOOTR, do you know whether it 
> represents the file name FOO or FOOTRUTF8 ?  And remember that the user 
> might provide a Unicode character stream identical to FOOTR: should it 
> be translated to FOO or FOOTRUTF8 when creating a new file according to 
> the user-supplied name?

If FOOTR is using PUA chars, then I believe that users should not be 
providing such a stream as it would have no defined meaning coming from 
them.