README.md

🌀 06_Functions_Recursion

Welcome to the Functions and Recursion section!
In this section, you’ll learn how to write modular, reusable, and organized code using functions — the foundation of clean and efficient Python programming.
You’ll also explore recursion, an advanced concept where functions call themselves to solve complex problems elegantly.

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📘 Overview

You will learn:

• How to define and call functions in Python.
• The use of parameters and return values.
• The concept of local vs global variables inside functions.
• What recursion is and how to apply it to repetitive problems.
• How to structure real-world programs efficiently using functions.

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🧩 Folder Structure

├── 06_Functions_Recursion/
│   ├── 01_functions_basics.py
│   ├── 02_return_and_parameters.py
│   ├── 03_global_variables_functions.py
│   ├── 04_recursion_basics.py
│   ├── practice_scripts/
│   └── README.md

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📂 Files Description

File Name	Description
01_functions_basics.py	Introduces what functions are, how to define them using def, and how to call them.
02_return_and_parameters.py	Demonstrates how to use parameters and return statements to make functions flexible and reusable.
03_global_variables_functions.py	Explains the difference between local and global variables, and how to use the global keyword.
04_recursion_basics.py	Introduces recursion — when a function calls itself — with examples like factorial and Fibonacci series.

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🧠 Example Code

# Basic Function Example
def greet():
    print("Hello, welcome to Python learning!")

greet()  # Calling the function


# Function with Parameters and Return Value
def add_numbers(a, b):
    return a + b

result = add_numbers(5, 3)
print("Sum:", result)


# Local vs Global Variables
x = 10  # Global variable

def change_value():
    global x  # Accessing global variable
    x = 20
    print("Inside function, x =", x)

change_value()
print("Outside function, x =", x)


# Recursion Example – Factorial Function
def factorial(n):
    if n == 1:
        return 1
    return n * factorial(n - 1)

print("Factorial of 5:", factorial(5))

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🧩 Practice Exercises

The practice_scripts/ folder includes beginner-to-intermediate problems designed to reinforce your understanding of functions and recursion.

Example Challenges:

• Write a function that checks whether a number is prime.
• Create a function that calculates the area of different shapes (circle, square, rectangle).
• Write a recursive function to calculate the factorial of a number.
• Build a recursive function to print Fibonacci numbers.
• Write a function that reverses a string using both loops and recursion.

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🚀 Next Section

Next Section → 07_File_IO

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