[Python-ideas] Changing the default install location, script versioning (Packages and PEP 370)

[Jesse Noller]

So, I've finally been able to kick my python 2.5 boat anchor, and I'm
now relishing in the delightful future of 2.6. Two things struck me
though, digging into PEP 370's (per user site-packages) behavior.

The first is this - when you install a package (say, pip) into the
.local directory via the --user command, the package ends up in the
correct lib directory; but the binary get dropped into ./local/bin -
this seems wrong. The reason being, is that what if I also have python
2.7 (which i do) installed, as well as python 3.1 and the
release-which-will-not-be-named (3.0) - if I install that same package
into one of the other versions, a new binary would be written with the
same name - a script-pythonversion might also be installed, but the
fact that the original script was overwritten seems broken to me.

I think the "best" fix for this is to make the bin/ directory mirror
the lib layout - each version would get it's own bin directory:

.local/
    bin/
        python2.6/
        python3.1/
    lib/
        python2.6/
        python3.1/

Of course, doing this begs the question - why have /bin and /lib be
top-level directories, instead favoring a layout which looks like:

.local/
    python2.6/
        bin/
        lib/

The data and doc directories which some packages might include should
follow the same convention, to avoid conflicts in those directories as
well.

The second behavior is more of a "man I wish for a unicorn" type of
thing - I think that --user should be removed, and by removed, I mean
made the default action when "python setup.py install" is invoked.
Users should need to instead pass in a --global flag to alter the
behavior to install into the system's site-packages and bin
directories. The reason is simple - installation to the global site is
typically a super-user task, and can side-effect all users, it's
growing into more of a no-no as more OS vendors grow to rely on the
packaged/included versions of python.

.002 cents

jesse