python module from source code - naming

A common pattern is to setup your project like this:

ProjectName/
|-- bin/
|   `-- myscript
|-- package_name/
|   |-- __init__.py
|   |-- rx.py
`-- setup.py

Your setup script then looks like:

#!/usr/bin/env python

from distutils.core import setup

setup(name='ProjectName',
      version='1.0',
      description='My project description',
      author='Me',
      author_email='Me@localhost',
      url='http://localhost/',
      packages=['package_name'],
     )

When you run:

$ python setup.py install 

Distutils will copy your package directory into site-packages.

With the above structure your imports would look like:

from package_name import Rx
print Rx.Factory

What it sounds like you want is:

import package_name
print package_name.Factory

To do that you'll want to add the following to your init.py:

from rx import Factory

For development you could symbolically link your package directory into site-packages but there are quite a few other ways to add development code to your PYTHONPATH without symbolic links.

The simplest way to do it is to simply change directory to your project directory (cd ProjectName based on the above example) and then just execute your script from there.

If you don't like that you could append your development package to your PYTHONPATH by doing something like:

$ export PYTHONPATH=$PYTHONPATH:/home/me/ProjectName

Yet another way to do it is to use a *.pth file to add your development package to the site-packages and have it still live in your home directory. To do this you'll just create a simple file called something like myproject.pth which will include:

# pth file for Rx development
/home/me/ProjectName

The nice thing about pth files is that you can move your code around, rename the package, add a second package, etc and it will still be importable without monkeying with your symlinks.

Of course there are other options like manipulation of sys.path in your user startup files, tools like virtualenv, buildout, etc.