firetest.py

#!/usr/bin/env python3.6
import fire # pypi.python.org/pypi/fire

class Example:
  def hello(self, name="world"):
    """Testing"""
    return f"Hello {name}!"

def main():
  fire.Fire(Example)

if __name__ == "__main__":
  main()

zOut.txt

$ python3 firetest.py
Type:        Example
String form: <__main__.Example object at 0x1028cf470>
File:        ~/firetest.py

Usage:       firetest.py
             firetest.py hello

$ python3 firetest.py hello
Hello world!

$ python3 firetest.py hello there
Hello there!