Functions in Python allow you to encapsulate a block of reusable code that performs a specific task. Here's an explanation of defining functions, function arguments and return values, as well as scope and variable visibility

Defining Functions

In this example, the function greet() takes a name parameter and returns a greeting message. The function is called with the argument "Alice", and the returned value is printed.

Function Arguments and Return Values

In this example, the add_numbers() function takes two arguments, a and b, where b has a default value of 0. The function returns the sum of a and b. When calling the function, you can provide both arguments or omit the second argument, in which case it takes the default value.


Scope and Variable Visability

In this example, the calculate() function has its own local variable x, which is separate from the global variable x. The local variable x is used within the function, and the global variable x is accessed outside the function.

Functions are essential for organizing code, promoting reusability, and making your program modular. They allow you to break down complex tasks into smaller, manageable units and improve the overall structure and readability of your code.