I met a very strange Python module loading behaviour in Pelican today :
https://github.com/getpelican/pelican/blob/3395e71/pelican/settings.py#L21

Here is some minimal code reproducing the issue. It requires 5 files :

bug_repro.py
dir_a/__init__.py
dir_a/test_data/pelicanconf.py
dir_b/__init__.py
dir_b/test_data/pelicanconf.py

bug_repro.py contains:

import dir_a
import dir_b

dir_a/__init__.py and dir_b/__init__.py both contain this code:

import os
from importlib.machinery import SourceFileLoader
print(SourceFileLoader('pelicanconf', os.path.dirname(__file__) + '/test_data/pelicanconf.py').load_module().THEME)

dir_a/test_data/pelicanconf.py contains only the line THEME = 'localized_theme' and dir_b/test_data/pelicanconf.py is empty.

What will produces python3.7 bug_repro.py ? 😉