python - Pythonic way to make subdirectories available to other subdirectories in my project

Thursday, 13 April 2017

Answer

How do I structure subdirectories in a python project, and make the code therein available to other subdirectories within the same project?

Example of what I'm finding difficult:

root/

+--- __init__.py
+--- foo/
     +--- __init__.py
     +--- foo.py
     +--- test/
          +--- foo_test.py

I have tried to use relative imports (as suggested in this SO answer)

In foo_test.py:

#!/usr/bin/python

from ... import foo

Attempting to run this from the command line:

$ chmod +x ./foo_test.py

$ ./foo_test.py

I get the following error:

Traceback (most recent call last):
  File "./foo_test.py", line 3, in 
    from ... import foo
ValueError: Attempted relative import in non-package

Question:

What is the pythonic way to make foo available to foo_test and other subdirectories which sit alongside foo?