How to fix “Attempted relative import in non-package” even with __init__.py

Question

I\'m trying to follow PEP 328, with the following directory structure:

pkg/
  __init__.py
  components/
    core.py
    __init__.py
  tests/
    core_test.py         


        

Answer 1

Issue is with your testing method,

you tried python core_test.py

then you will get this error ValueError: Attempted relative import in non-package

Reason: you are testing your packaging from non-package source.

so test your module from package source.

if this is your project structure,

pkg/
  __init__.py
  components/
    core.py
    __init__.py
  tests/
    core_test.py
    __init__.py

cd pkg

python -m tests.core_test # dont use .py

or from outside pkg/

python -m pkg.tests.core_test

single . if you want to import from folder in same directory . for each step back add one more.

hi/
  hello.py
how.py

in how.py

from .hi import hello

incase if you want to import how from hello.py

from .. import how