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.

score 1 · Accepted Answer · answered Mar 05 '18 at 23:14

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

answered Mar 05 '18 at 23:14

Nebbles

113
7

Besides your answer, that link you researched is great. – progmatico Mar 06 '18 at 14:56

score 0 · Answer 2 · answered Mar 05 '18 at 16:02

0

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.

answered Mar 05 '18 at 16:02

progmatico

4,714
1
16
27

Thanks for this, certainly helped with researching the answer – Nebbles Mar 05 '18 at 23:15

Python/PyCharm: Differences when running subpackage modules

2 Answers2