**README** for SetupHelper Version 0.4.2

:Author:        Peter A. Donis
:Release Date:  12 March 2008

SetupHelper: Automating Boilerplate in Python Setup Scripts
===========================================================

This Python module will make your setup scripts simpler to
write, by automating as much as possible of the 'boilerplate'
that normally goes into them. Instead of invoking the ``setup``
function with a long list of keyword arguments, you just set
global variables in your setup script and then invoke the
``setup_main function``, passing ``globals()`` as its argument.
(The SetupHelper setup.py script itself illustrates this usage.)

The helper module does all the grunt work of translating your
variables into keyword arguments, including automatically
deducing and generating many arguments so that you only have
to specify a much simpler set of data. As a bonus, if you are
using Python's standard distutils, SetupHelper provides (very
basic!) support for the ``requires`` keyword, downloading and
installing required packages for you, as long as their download
URLs are available on PyPI. (You can also specify a local
directory as a "repository" by setting the environment
variable ``PYPI_LOCAL`` to point to it--see the ``CHANGES``
file in the source archive for details.) This functionality
currently does *not* support version specifiers after the
package name (unless you are using setuptools, which does
allow this--see below).

(Note that the Python 2.5 and later distutils package allows
the ``requires`` keyword in distribution metadata, but does
not actually use it to install anything for you. Of course
some distutils replacements like setuptools do provide this
functionality; if you are using setuptools, you can set the
variable ``__distutils_pkg__`` to ``'setuptools'`` and
SetupHelper will use setuptools' support instead of its own,
which has some additional features, such as allowing version
specifiers for required packages. SetupHelper also adds the
``requires``, ``provides``, and ``obsoletes`` keywords to
your package metadata when you use the ``setup.py register``
command with Python versions < 2.5; in other words, it gives
you support for metadata version 1.1 even if your Python
version doesn't.)

Since SetupHelper has all the information needed to determine
what should be in your source or binary distribution files,
it auto-generates ``MANIFEST.in`` each time it runs, so you don't
have to maintain your ``MANIFEST.in`` file manually (and if you
did, it would get overwritten anyway). Even though it is not
strictly necessary to write ``MANIFEST.in`` unless you are running
a distribution command, SetupHelper does it every time because
checking its output can often help you debug problems with the
variable definitions in your setup script. (At least, it has
certainly helped *me* to do that!)

Using SetupHelper as an Installer
---------------------------------

This distribution includes a script, ``setuphelper``, that you
can use to leverage SetupHelper's ``requires`` keyword support
to use it as an installer. Command line arguments to the
script are treated as a list of requirements to be installed,
and the script uses SetupHelper to download and install them,
just as if they were listed in a ``setup.py`` script. If you
want to use setuptools' ``easy_install`` support with this
technique, use the command line option ``--use-setuptools``
(short form ``-s``).

Since this script uses the ``requires`` keyword functionality
in SetupHelper, it has the limitation noted above, that no
version specifiers can currently be used after package names.

Post-Install Script Support
---------------------------

As one other bonus, SetupHelper allows you to automate the
running of post-install scripts; just set the ``__post_install__``
variable in your ``setup.py`` to a list of script names to be run
from a subshell (this is done using ``os.system``, so it has the
limitations of that Python command). It is desirable to allow
post-install scripts to be run from ``setup.py`` so that SetupHelper
can ensure that any required packages are fully installed by
just calling ``python setup.py install`` on them once they are
unpacked. (Note that, if you are using setuptools, this feature
does not work, as setuptools does not actually run
``python setup.py install`` to install your package. A future
version of SetupHelper might lift this constraint.)

Installation
------------

Of course, to install SetupHelper, you can simply type::

    $ python setup.py install

in the directory where you unpacked the SetupHelper archive.
However, since SetupHelper is used by setup scripts, you will
probably want to include it along with your ``setup.py`` in the
source archives for your Python projects as well as having it
installed on your own system.

Copyright and License
=====================

SetupHelper is Copyright (C) 2008 by Peter A. Donis. It is
released under the Python Software Foundation license, so
you can use and redistribute it just as you do Python itself.
