Lecture
This lecture covers the concept of functions in Python, which allow grouping code to be executed later, simplifying code development and maintenance. It introduces keywords like def, return, global, and nonlocal. The lecture explains predefined and user-defined functions, formal and effective parameters, and the importance of docstrings. It also discusses the execution of functions, including the use of default and optional parameters, as well as the handling of mutable default values. Examples of function calls with various arguments are provided, showcasing the flexibility and power of Python functions.