绝对导入导致 ModuleNotFoundError

Question

Python 3.6

I've written some components and I'm trying to import one of them in the other.

Below is what my project structure looks like:

.
└── components
    ├── __init__.py
    ├── extract
    │   └── python3
    |       ├── __init__.py
    │       └── extract.py
    └── transform
        └── python3
            ├── __init__.py
            └── preprocess.py

extract.py

from components.transform.python3.preprocess import my_function

if __name__ == '__main__':
    my_function()

preprocess.py

def my_function():
    print("Found me")

When I run python components/extract/python3/extract.py

I see the following error:

ModuleNotFoundError: No module named 'components'

I've added an empty __init__.py file to the directories that contain modules as well as the top level package directory.

Answer 1

Ok, imports require the top level package to be available in Python PATH ( sys.path ).

So to make it work, you should:

• cd to the directory containing components

• add . to the Python PATH:

   export PYTHONPATH='.'

• launch your script:

   python components/extract/python3/extract.py

On my system, it successfully displays:

Found me