Running python scripts from github etc

[supuflounder]

Hi.
I sometimes find some python scripts on github for example that I want to try out, but the documentation doesn't include instructions how to run the script. For me as a newbie I don't where to turn, maybe you can point me in the right direction?

So for example, i want to run this https://github.com/molobrakos/tellsticknet .
I've downloaded the source as a zip file and extracted it, and I've tried invoking the different py-files from console by typing python3 xxx.py but I just run into "no module named '...'" errors.
How do I get these missing modules?

Well, if you told us what the module names were, it might help. Are they modules of the files you downloaded, or standard modules?