Once you can make decisions and repeat work, the next step is packaging that logic into reusable pieces. This module covers how to define functions, control where your variables live, and write functions flexible enough to take any number of arguments.
It starts with defining functions: parameters,
default values, and return statements. From there it covers
scope — the difference between local and global
variables, and how Python decides which one a function actually
sees. It continues with *args and **kwargs, for
writing functions that accept a variable number of positional or
keyword arguments, and closes with lambda
functions, small anonymous functions often used with
filter(), map(), and reduce().
Watch the lessons in order, then continue on to Modules, Packages & Environments.
Defining your own functions, working with parameters and default values, and returning values back to the caller.
How Python resolves variable names inside and outside of functions, and why relying on global state can cause hard-to-find bugs.
Letting a function accept an arbitrary number of positional arguments with *args and keyword arguments with **kwargs.
Writing small, anonymous functions with lambda, and using them alongside filter(), map(), and reduce() for quick data transformations.