Probably, it’s one of the most common tasks: running some scripts as another user and not being root. Here’s a solution.
1. Run visudo. If you don’t have it make sure you have sudo installed.
2. Add next line:
myuser ALL=(anotheruser) NOPASSWD: /home/anotheruser/bin/script.py
sudo -u anotheruser /home/anotheruser/bin/script.py