sys

What it is good for?

Settings of the Python interpreter itself.

The sys module provides an access point to the Python environment. You find there command line arguments, the import path settings, the standard input, output and error stream and many more.

Installed with Python by default

yes

Example

Command line parameters used when calling Python:

  1. import sys
  2. print(sys.argv)

Version of the Python interpreter:

  1. print(sys.version)

Directories in which Python looks for modules:

  1. print(sys.path)

Exit Python altogether:

  1. sys.exit()

Where to learn more?

https://docs.python.org/3/library/sys.html