Try input this command:

pip install setuptools distutils-pytest

Python doesn't know that the directory containing your modules (including main.py) is a package, therefore it can't properly locate imports. Create an empty __init__.py file in this directory to mark it as a regular package.

A rule of thumb is to mark all your directories that contain python modules as packages with this method.

There's another type of Python packages that may make your code sometimes work: namespace packages. They don't have to contain an __init__.py file. I recommend to just avoid them, unless you understand exactly what they're for and why you need them. [Doc reference]

For a quick reference, search through the FastAPI documentation for "project file structure" (it may be called something similar).

Your init() call in main.py needs to be in an if __name__ == '__main__': block, and you should not set __name__ yourself - Python will do that automatically.

Otherwise your circular imports will cause helper to not be imported properly before init() is called. The sequence as it stands is going like this:

1. You run main.py, which starts main.py being evaluated.
2. The import helper line in main.py starts helper.py being evaluated.
3. The import main line in helper.py starts another evaluation of main.py because the main module has not been previously imported.
4. The import helper line in the second evaluation of main.py imports the existing helper object that was created when #2 started helper being imported, so this doesn't create an infinite loop - but the existing helper object hasn't fully loaded yet; it's still waiting for the main import to resolve.
5. The second evaluation of main hits the init() call at the bottom of main.py, which tries to run init() - but helper still isn't done loading, and thus the way_out_quest function in helper.py hasn't been evaluated yet and thus is not defined.

In general, it's best to avoid circular imports in the first place - then you don't have to worry about problems like this.