## Introduction

In this project, you will learn how to calculate the factorial of a non-negative integer. The factorial of a positive integer is the product of all positive integers less than or equal to it, and the factorial of 0 is 1.

### 👀 Preview

```
$ python factorial.py
2! = 1 * 2 = 2
8! = 1 * 2 * 3 * 4 * 5 * 6 * 7 * 8 = 40320
```

### 🎯 Tasks

In this project, you will learn:

- How to create a
`factorial.py`

file in the`~/project`

directory - How to implement the
`factorial`

function to calculate the factorial of a non-negative integer - How to handle negative inputs by raising a
`ValueError`

and display a prompt saying "Please enter a non-negative integer"

### 🏆 Achievements

After completing this project, you will be able to:

- Understand the concept of factorial and how to calculate it
- Write a Python function to calculate the factorial of a non-negative integer
- Handle input errors and display appropriate error messages
- Apply your knowledge of Python programming to solve a real-world problem