How do I import from a package in a subdirectory?

Python Help
1

I have David Eppstein’s PADS library of Python Algorithms and Data Structures in a subdirectory next to my Python script:

- my-script.py
- PADS
    - __init__.py
    - Automata.py
    - Util.py
    - ...

How can I use the RegExp class in my script? It’s defined in PADS/Automata.py but when I use import PADS.Automata, I get an error from a line inside that file:

  File ".../PADS/Automata.py", line 9, in <module>
    from Util import arbitrary_item
ModuleNotFoundError: No module named 'Util'
2

The original version of that was written in 2003. Automata.py, will only work when run from within the PADS dir, where it can find Util.py (unless you want to to hack around with sys.path).

There are almost certainly much better, modern, maintained, alternatives.

Unfortunately this version on PyPi repackaged by Timothy doesn’t work any better. PADS really needs updating, or at least its imports refactoring to make it installable and usable from any directory.