[Python-3000] [Python-Dev] Patch for an initial support of bytes filename in Python3

[Guido van Rossum]

On Tue, Sep 30, 2008 at 6:21 AM,  <glyph at divmod.com> wrote:
> On 12:47 am, victor.stinner at haypocalc.com wrote:
>
> This is the most sane contribution I've seen so far :).

Thanks. I'll review it later today (after coffee+breakfast :) and will
apply it assuming the code is reasonably sane, otherwise I'll go
around with Victor until it is to my satisfaction.

>> See attached patch: python3_bytes_filename.patch
>>
>> Using the patch, you will get:
>> - open() support bytes
>> - listdir(unicode) -> only unicode, *skip* invalid filenames
>>  (as asked by Guido)
>
> Forgive me for being a bit dense, but I couldn't find this hunk in the
> patch.  Do I understand properly that (listdir(bytes) -> bytes)?
>
> If so, this seems basically sane to me, since it provides text behavior
> where possible and allows more sophisticated filesystem wrappers (i.e.
> Twisted's FilePath, Will McGugan's "FS") to do more tricky things,
> separating filenames for display to the user and filenames for exchange with
> the FS.
>>
>> - remove os.getcwdu()
>> - create os.getcwdb() -> bytes
>> - glob.glob() support bytes
>> - fnmatch.filter() support bytes
>> - posixpath.join() and posixpath.split() support bytes
>
> It sounds like maybe there should be some 2to3 fixers in here somewhere,
> too?  Not necessarily as part of this patch, but somewhere related?  I don't
> know what they would do, but it does seem quite likely that code which was
> previously correct under 2.6 (using bytes) would suddenly be mixing bytes
> and unicode with these APIs.

Doesn't seem easy for 2to3 to recognize such cases.

If 2.6 weren't pretty much released already I'd ask to add
os.getcwdb() there, as an alias for os.getcwd(), and add a 2to3 fixer
that converts os.getcwdu() to os.getcwd(), leaves os.getcwd() alone
(benefit of the doubt) and leaves os.getcwdb() alone as well (a strong
indication the user meant to get bytes in the 3.x version of their
code. (Similar to using bytes instead of str in 2.6 even though they
mean the same thing there -- they will be properly separated in 3.x.)

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