ImportError when trying to import a custom module in Python

Question

Note that I searched SO for this error and while there were many similar questions, I didn't find one that addressed this particular issue.

I'm working on a Python module that looks like this:

/com
    /company
        /foo
        /bar

I'm editing a source file within the bar directory and attempting to import classes that live in the foo directory. I've tried importing the files the following ways:

from com.company.foo import *
from company.foo import *
from foo import *
import com.company.foo
import company.foo
import foo

Each of these produces a similar error:

ImportError: no module named com.company.foo

I have __init__.py files in each of the directories, including the directory that contains com.

Not sure what I'm doing wrong here - thanks in advance for you assistance!

Answer 1

The directory containing /com needs to be on the Python path. There are a number of ways to do this:

1. At the command line, every time:

   user@host:~$ PYTHONPATH=/path/to/whatever python some_file.py

2. In your shell configuration (.bashrc, .bash_profile, etc):

   export PYTHONPATH=/path/to/whatever

3. In Python code (I don't recommend this, as general practice):

   import sys
   sys.path.append('/path/to/whatever')

As some of the commenters said, usually this is handled either by the container (mod_wsgi, etc) or by your bootstrap/main script (which might do something like option #3, or might be invoked in an environment set up as in options #1 or #2)