The sys module provides access to functions and values concerning the program's runtime environment, such as the command line parameters in
sys.argv or the function
sys.exit() to end the current process from any point in the program flow.
While cleanly separated into a module, it's actually built-in and as such will always be available under normal circumstances.
Import the sys module and make it available in the current namespace:
Import a specific function from the sys module directly into the current namespace:
from sys import exit
For details on all sys module members, refer to the official documentation.