setup.py and installing a python project

Question

I've looked through the setup.py documentation and am still having some difficulties with what I feel should be pretty basic.

I've broken this down to a simple example project that I'm trying to get running, my project's directory layout is as follows:

myproject
  setup.py
  src\
    main.py
      extern\
      __init__.py
      mytest.py

myproject/setup.py:

#!/usr/bin/env python
from distutils.core import setup

setup(name = "myproject",
      package_dir = {'':"src"},
      packages = ["extern"],
      scripts = ["src/main.py"],
      )

myproject/src/main.py:

#! /usr/bin/env python
import extern.mytest as mytest

mytest.print_test()

myproject/src/extern/mytest.py:

#!/usr/bin/env python
def print_test():
    print "YAY"

myproject/src/extern/_init_.py is blank.

I'm running setup.py as:

setup.py install --prefix ~/local

setup.py will complete with no errors and move main.py to ~/local/bin however when I run it I get the following error:

ImportError: No module named extern.mytest

Any idea what I'm doing wrong? Thanks!

Answer 1

The problem is that the module isn't under sys.path and that's way it cannot be found by the import statement.

In my case, the extern module was installed under ~/local/lib/python2.7/site-packages/extern. However, note that the installation path was arbitrarily set to ~/local during the installation.

To fix that, you can set your PYTHONPATH variable to the location where the module is installed or add that path to sys.path in main.py.

Alternatively, instead of:

setup.py install --prefix ~/local

use:

setup.py install --user

This will install in your user site packages directory (~/.local in my platform) and python will be able to find the package without any problem. However, you'll probably need to change your PATH environment variable to include ~/.local/bin.