Transform run_examples.py from Python 2 to Python 3

[linhbngo]

Is your feature request related to a problem? Please describe.

With Python 2 is no longer being supported/updated, can the run_examples.py be converted to Python 3?

Describe the solution you'd like

A conversion of run_examples.py to Python 3

[rsdefever]

Hi @linhbngo! Hope all is well there. I didn't know you used Cassandra.

I can definitely take care of this. We have already migrated the library_setup.py and mcfgen.py. Is this urgent?