Safe exit for command line applications in python.

script.py

import sys

def cli_function():
    """This is a python function that offers a CLI or does some long running
    task that you might want to interrupt"""
  
  
if __name__ == "__main__":
    try:
        cli_function()
    except KeyboardInterrupt as e:
        print("User interruption", file=sys.stderr)
        sys.exit(1) # 1 = user interruption