[Python-ideas] Fixing __file__ to be absolute

[Brett Cannon]

On Thu, Jan 2, 2014 at 8:46 AM, anatoly techtonik <techtonik at gmail.com>wrote:

> On Thu, Jan 2, 2014 at 4:28 PM, Brett Cannon <brett at python.org> wrote:
> > On Thu, Jan 2, 2014 at 7:37 AM, Tal Einat <taleinat at gmail.com> wrote:
> >> On Wed, Jan 1, 2014 at 9:01 PM, anatoly techtonik <techtonik at gmail.com>
> >> wrote:
> >> > Fixing this thing will make my happy (or very sad if you'd like this).
> >> >
> >> > Problem is described here:
> >> > http://stackoverflow.com/a/6416333/239247
> >> > Summary:
> >> > 1.  chdir()
> >> > 2.  dirname(__file__)
> >> > 3.  FAIL
> >> >
> >> > Proposal:
> >> > from __future__ import abs__file__
> >>
> >> Anatoly, this subject was already discussed on this list, just three
> >> months ago, in a thread you started! [1]_
> >>
> >> To quote one of Nick Coglahan's replies [2]_:
> >>
> >> > Note that any remaining occurrences of non-absolute values in __file__
> >> > are
> >> > generally considered bugs in the import system. However, we tend not
> to
> >> > fix
> >> > them in maintenance releases, since converting relative paths to
> >> > absolute
> >> > paths runs a risk of breaking user code.
> >>
> >> > We're definitely *not* going to further pollute the module namespace
> >> > with
> >> > values that can be trivially and reliably derived from existing
> values.
> >
> >
> > This was also changed in Python 3.4 back in October:
> > http://hg.python.org/cpython/rev/76184b5339f2
>
> Thanks. That's just what I was looking for - a status update.
> Links in emails are not telling anything about progress being
> made, roadmap, problems and versions of Python. Seem like
> tracker is a poor tool to track this stuff too.
>

It's not in released code yet so there is no way to really promote this in
a way that is guaranteed not to change. It will be in the What's New doc
for Python 3.4, though, when the final version is released:
http://docs.python.org/3.4/whatsnew/3.4.html#other-language-changes


>
> Now in spite of recent Python 3 status update, the question is how
> possible to make this feature more visible and implemented in
> previous version as from __future__ import abs__file__?
>

There is no chance that will ever happen.


>
> I'd like to ask for two perspectives:
> 1. technical feasibility
>

I don't see why it wouldn't be technically possible since I made it work in
Python 3.4.


> 2. political obstacles (backward compatibility policy / process obstacles),
>     even if they are obvious
>

It would be a total break in backwards-compatibility by adding a new
feature in a bugfix release and that's never acceptable (and that rule has
been in effect since Python 2.2.1).


>
> Also, what is the process of nominating this features to selection in
> Python 2.8 (or whatever comes out of this incremental development idea)?
>

There is no future Python 2.8 release so there is no process to nominate
something; PEP 404 is very clear on this:
http://python.org/dev/peps/pep-0404/ . And there is no "incremental
development idea" or something that's going to change the current
development process of Python so that part of the questions doesn't make
sense to me.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/python-ideas/attachments/20140102/83613241/attachment.html>