Let's assume I have two parallel directories, with simple python files. 'dir_one' with file_one.py 'dir_two' with file_two.py In file_one.py there is a function named function_one. How can I import it in file_two.py? I have checked literally a few dozens of sources, including answers on stackoverflow. Therefore, I am not quoting any of them here. I have tried four different solutions, none of them worked: Insert 'init.py' files in all the directories - results in error 'ImportError: attempted relative import with no known parent package' Make both directories a single package - not possible in this case, directories have to be able to run as independent apps. Use sys module: sys.path.insert(0, 'path-to-dir_one') right before 'import dir_one' line - doesn't change anything, still get 'ModuleNotFoundError: No module named 'dir_one'. try relative import: 'from .dir_one import file_one' - 'ModuleNotFoundError: No module named 'zweizen.prodalitics'. Is it possible at all to import a function in python from parallel folder without making it part of the same package? Continue reading...