[Distutils] Beginning of support for binary distributions

[Greg Ward]

Hi all --

I've just checked in the beginnings of support for creating "built
distributions" (aka binary distributions, but of course they aren't
necessarily binary -- you might want to distribute something that is
immediately installable but contains only Python code).

This consists of two commands so far, 'bdist' and 'bdist_dumb'.  These
follow the model of the 'build' and 'install' families, where there is
one high-level coordinator, and "sub-commands" that do the real work.
So far, obviously, there's only one bdist sub-command, and all it
creates are "dumb" built distributions -- tarballs and zip files that
you unpack from <prefix> or <exec-prefix>.

There are a number of obvious weaknesses to this, but this was intended
more as a warm-up exercise than the real thing.  First of all, the end
user has to somehow know to chdir to Python's <prefix> or <exec-prefix>
and unpack the dumb distribution there.  Worse, they have to know to
sometimes chdir to to <prefix>, and sometimes <exec-prefix> -- assuming
there's even a difference on their system.  Anyways, as I said, this is
*not* the be-all, end-all to creating built Python module distributions!
However, it's all that I could whip up in three evenings.

If you'd like to try it out, please do!  Here's the basic idea:

    python setup.py bdist
or:
    python setup.py bdist --formats=gztar    # or zip, tar, or ztar

The default format is currently gztar for Unix, zip for Windows.
Obviously, that will have to get a bit more complicated: we'll want to
create an RPM on RPM-based systems, a Debian package on Debian systems,
a BSD package on BSD systems, some sort of executable installer
(probably Wise) on Windows systems, etc.  But for now, you get either a
tarball or a zipfile, and if you don't specify --formats, you get
whatever is sensible on your current OS.

For example, if I go to my NumPy 15.2 directory (which is identical to
the NumPy 15.2 distribution, *except* I use the example NumPy setup
script included with the Distutils!) and run this:

  $ python setup.py bdist 

then I get (roughly) this output:

  [...build output omitted...]
  creating build/bdist
  creating build/bdist/lib
  creating build/bdist/lib/python1.5
  creating build/bdist/lib/python1.5/site-packages
  creating build/bdist/lib/python1.5/site-packages/Numeric
  hard linking build/lib.linux-i586/ArrayPrinter.py -> build/bdist/lib/python1.5/site-packages/Numeric
  hard linking build/lib.linux-i586/FFT.py -> build/bdist/lib/python1.5/site-packages/Numeric
  [...and so on, for all modules that NumPy would install...]
  changing into 'build/bdist'
  tar -cf /scratch/python/Numerical-15.2/Numerical-15.2.linux-i586.tar .
  gzip /scratch/python/Numerical-15.2/Numerical-15.2.linux-i586.tar
  changing back to '/scratch/python/Numerical-15.2'

and the resulting tarball, Numerical-15.2.linux-i586.tar.gz, looks like
this:

  $ tar tzf Numerical-15.2.linux-i586.tar.gz
  ./
  lib/
  lib/python1.5/
  lib/python1.5/site-packages/
  lib/python1.5/site-packages/Numeric/
  lib/python1.5/site-packages/Numeric/ArrayPrinter.py
  lib/python1.5/site-packages/Numeric/FFT.py
  lib/python1.5/site-packages/Numeric/LinearAlgebra.py
  [...]
  lib/python1.5/site-packages/Numeric/ranlib.so
  lib/python1.5/site-packages/Numeric/arrayfns.so

which reduces installing Numerical Python to a mere

  $ cd `python -c "import sys; print sys.exec_prefix"`
  $ tar xzvf /scratch/python/Numerical-15.2/Numerical-15.2.linux-i586.tar.gz

OK, OK, so it's not immediately obvious that this is better than a
simple "python setup.py install".  ;-)  But think of the possibilities!

Known bugs:

  * if a distribution needs a .pth file, it is neither created nor
    included in the built distribution

Feel free to add to this list...

        Greg
-- 
Greg Ward - just another /P(erl|ython)/ hacker          gward@python.net
http://starship.python.net/~gward/
If it can't be expressed in figures, it is not science--it is opinion.