Python/PyCharm: Differences when running subpackage modules

Question

I have a project subdivided into packages, in the following structure:

/project
    /pkg
        __init__.py
        engine.y
        ai.py
    __init__.py
    test_script.py

engine.py has an import statement to use ai.py which looks like

import pkg.ai as ai

This means that test_script.py can be run in the command line as python test_script.py and it has no issues. However for debugging purposes, engine.py is also often run. When running in PyCharm it has no problems but when using python engine.py I get errors saying No module named pkg .

Is there any way I can run engine.py in the command line so that it does not have import errors the way PyCharm does it?

Interestingly the way PyCharm works is that if I do not put that pkg. in front of the import module, it underlines it in red saying it can't find the module (but still runs). I've looked everywhere for a solution to this but have only got more confused.

Answer 1

The best explanation to this issue was explained here . In short, keep the absolute imports with import pkg.ai in engine.py but when I want to run the engine module for testing reasons it should be run on the top level (when in project dir) with the module flag, such as:

cd project/
python -m pkg.engine

Answer 2

Make something similar to what you've done with test_script.py In the same script or in another one in the same level and invoke the scripts from there.

You may also want to read my two answers here and here , they contain two examples on how to use import packages. That should help you understand their usage.