Basic Python imports question

Question

If I have a src directory setup like this:

main.py
pkg1:
    __init__.py
    util.py
pkg2:
    __init__.py
    test.py

Can you tell me the best way to import pkg1.util from main.py and from test.py?

Thanks! (If I need to have another __init__.py file in the root directory, let me know?)

Answer 1

Since you mention that this is Python 3, you do not have to add the following to your .py files. I would still though because it helps backwards portability if some poor sod who's stuck on Python 2 needs to use your code:

from __future__ import absolute_import

Given that you are using Python 3, or that you're using Python 2 and have included the above line, here is your answer:

From main.py:

import pkg1.util as util

from test.py you would use one of two ways depending on whether you considered pkg1 and pkg2 to be things that would always deployed together in the same way in relation to each other, or whether they will instead always be each deployed semi-independently at the top level. If the first, you would do this:

from ..pkg1 import util

and if it's the second option, this:

import pkg1.util as util

This implies, of course, that you are always running Python from the directory in which main.py is, or that that directory is in PYTHONPATH or ends up in sys.path for some reason (like being the main Python site-packages directory for example).