Best way to install python packages locally for development

Question

Being new to the python games I seem to have missed out on some knowledge on how you can develop on a program but also keep it in your live environment.

Programs like gpodder can be run directly from the source checkout which is really handy however others want to be "installed" to run.

A lot of programs are distributed with a setup.py with instructions to run "python ./setup.py install" as root which will put stuff somewhere in your file-system. There are even install commands like "develop" which seem to hold the promise of what I want. So I tried:

export PYTHONPATH=/home/alex/python
python ./setup.py develop --install-dir=/home/alex/python

Which downloaded a bunch of stuff locally and seems magically ensure the application I'm hacking on is still being run out of the src tree. So I guess my roundabout question is is this the correct way of developing python code? How do things like easy_install and pip factor into this?

EDIT TO ADD

So I tried the following:

 python /usr/share/pyshared/virtualenv.py /home/alex/src/goobook
 cd /home/alex/src/goobook/googbook.git
 /home/alex/src/goobook/bin/python ./setup.py develop

And finally linked the program in question to my ~/bin

 cd /home/alex/src/goobook
 linkbin.pl bin/goobook

However invocation throws up a load of extra chatter which seems to imply it's wrong:

17:17 alex@socrates/i686 [goobook] >goobook --help
/home/alex/bin/goobook:5: UserWarning: Module pkg_resources was already imported from        /home/alex/src/goobook/lib/python2.5/site-packages/setuptools-0.6c8-py2.5.egg/pkg_resources.py, but /home/alex/src/goobook/lib/python2.5/site-packages/distribute-0.6.10-py2.5.egg is being added to sys.path
  from pkg_resources import load_entry_point
/home/alex/bin/goobook:5: UserWarning: Module site was already imported from /home/alex/src/goobook/lib/python2.5/site.pyc, but /home/alex/src/goobook/lib/python2.5/site-packages/distribute-0.6.10-py2.5.egg is being added to sys.path
  from pkg_resources import load_entry_point

Answer 1

Install:

http://pypi.python.org/pypi/virtualenv

to set up a localized virtual environment for your libraries, and:

http://pypi.python.org/pypi/setuptools

i.e. "easy_install" to install new things.

Answer 2

The best way to develop python apps with dependencies is to : 1) Download desired version of the python interpreter 2) Install and use buildout (http://www.buildout.org/)

Buildout is something like Maven for java ( will fetch all needed packag automatically )

This way your python interpreter will not be polluted by third party packages ( this is important if you will be running developed application on other machines). Aditionally you can integrate buildout with virtualenv package ( this allows you to create virtual python interpreters for each project).