Python cannot find module in same folder-CodePudding

I have truly tried my best to understand python imports, but it makes no sense to me. I know there's a million SO threads on this but none of them have helped me understand what's going on.

I have this simple structure:

project/
    run.py
    datasets/
        __init__.py
        config.py
        datasetA.py

datasetA.py:

from config import classes
dosomething()

run.py:

from datasets import datasetA

And when I execute run.py, I get ModuleNotFoundError: No module named 'config'. Why? I have tried to include

import datasetA
import config

as well as

import .datasetA
import .config

in __init__.py but it makes no difference. datasetA sees __package__ = datasets, so it I think it should see config. run.py sees __package__ = None. What am I missing?

CodePudding user response：

Relative vs absolute imports

Your issue relates to the differences between relative and absolute imports. When you try to import config from datasetA, python looks in the root directory, in this case, project/. To fix this, what you want to do is use a relative import in datasetA. See the difference between the following:

# project/datasets/datasetA.py

# Absolute import
from config import classes

# Python checks for an available import at the root of the project
# (e.g. project/ in this case) and fails as it does not exist

# Relative import
from .config import classes

# Python checks in the current directory
# (e.g. project/datasets/) and succeeds

You can read more about relative and absolute imports here