sys
The sys module is a built-in Python library that provides access to system-specific parameters and functions, such as command-line arguments, interpreter settings, and runtime environment details. It allows developers to interact with the Python interpreter and the underlying operating system, enabling tasks like script termination, path manipulation, and version checking.
Developers should learn the sys module when building Python applications that require system-level control, such as command-line tools, scripts with configurable behavior, or programs needing environment-specific adjustments. It is essential for handling command-line arguments via sys.argv, managing Python's module search path with sys.path, and gracefully exiting scripts using sys.exit().