Summary  
This chapter explains how to define functions within other functions in Python, detailing scope rules (including nonlocal), and how nested functions enable closures and decorators to produce reusable, modifiable behavior.

General domain of usage  
Creating decorators to wrap and extend function behavior (e.g., for logging, access control, or memoization)

This topic will not only help understand the **nonlocal** scope but also **closures** and **decorators**.

Functions are **first-class citizens** in Python. They can be:
- Passed as arguments to functions;
- Returned from functions; 
- Modified;
- Assigned to variables.

Let's explore some examples:

``` python
def outer_function(...):
	...
    def inner_function(...):
		...
	return ...
```

In programming, a **nested function** is a function that is defined inside another function.

def count_percent(num1, num2, num3):
	def inner(num):
		return num * 30 / 100
	return (inner(num1), inner(num2), inner(num3))

print(count_percent(700, 300, 1000))

Useful if you want to perform a complex task multiple times within another function without repeating code.



In this course, you will learn advanced topics such as function arguments, iterators, generators, closures, and decorators. Dozens of practice exercises will help you grasp these topics.

You'll find this topic enjoyable, and you'll learn how to pack and unpack values in a single assignment.

Explore the power of Python's function arguments, *args, **kwargs, and learn how to effectively use functions as arguments.

Discover the higher-order functions and how functions can be passed as arguments to other functions in programming.

What is variable scope, and how did we manage without it before? This topic is essential for understanding the following subjects: Closures and Decorators. I assure you that this topic will be both enjoyable and practical. You will gain knowledge about local, nonlocal, and global variables.

This section provides an in-depth exploration of Python decorators, a powerful feature that allows for the modification and enhancement of function behavior. Participants will learn how to write their own decorators, understand built-in decorators, and apply decorators in practical scenarios.

Nested Functions in Python: Scope and Accessibility

Nested Functions in Python: Scope and Accessibility