1. Introduction

1.1 Goal of the Tutorial

This tutorial aims to provide an in-depth exploration of Python's built-in exceptions. Understanding these exceptions will allow you to handle errors effectively in your Python programs.

1.2 Learning Outcomes

By the end of this tutorial, you should be able to:

• Understand the concept of exceptions in Python
• Identify and use Python's built-in exceptions
• Handle exceptions using try, except, finally blocks

1.3 Prerequisites

Basic knowledge of Python programming is required. Familiarity with Python's syntax and control flow (such as if statements and loops) would be beneficial.

2. Step-by-Step Guide

Exceptions in Python are events that occur when an error happens during program execution. When a Python script raises an exception, it must either handle the exception immediately or it will terminate and quit.

Python provides several built-in exceptions, such as ZeroDivisionError, TypeError, ValueError, FileNotFoundError, etc. These exceptions can be triggered when your program encounters an error.

2.1 Catching Exceptions

To catch exceptions, use try and except blocks. The code that could potentially raise an exception goes in the try block. The code that handles the exception goes in the except block.

try:
    # Code that might raise an exception
except ExceptionType:
    # Code to handle the exception

2.2 Built-in Exceptions

Here are some commonly used built-in exceptions:

• ZeroDivisionError: Raised when the second operator in the division is zero.
• TypeError: Raised when an operation or function is applied to an object of inappropriate type.
• ValueError: Raised when a function receives an argument of the correct type but inappropriate value.
• FileNotFoundError: Raised when trying to open a file that does not exist.

3. Code Examples

Let's look at some examples of these exceptions:

3.1 ZeroDivisionError

try:
    x = 1 / 0  # Division by zero
except ZeroDivisionError:
    print("You can't divide by zero!")

# Expected output: You can't divide by zero!

3.2 TypeError

try:
    '2' + 2  # String and integer addition
except TypeError:
    print("You can't add a string to an integer!")

# Expected output: You can't add a string to an integer!

3.3 ValueError

try:
    int('Python')  # Invalid literal for int()
except ValueError:
    print("Invalid value for integer conversion!")

# Expected output: Invalid value for integer conversion!

3.4 FileNotFoundError

try:
    with open('non_existent_file.txt') as f:  # File does not exist
        print(f.read())
except FileNotFoundError:
    print("File not found!")

# Expected output: File not found!

4. Summary

We've covered:

• The concept of exceptions in Python
• How to catch exceptions using try and except blocks
• Some common built-in exceptions in Python

Next, you should learn about creating your own custom exceptions and how to raise exceptions manually using the raise statement. The Python documentation is a great resource for this.

5. Practice Exercises

1. Write a program that catches a TypeError when trying to concatenate a string and an integer.
2. Write a program that catches a ValueError when trying to convert a string that does not represent an integer.
3. Write a program that catches a FileNotFoundError when trying to read a file that does not exist.

Solutions

try:
    result = 'Hello' + 1
except TypeError:
    print("TypeError caught!")

# Expected output: TypeError caught!

try:
    number = int('Hello')
except ValueError:
    print("ValueError caught!")

# Expected output: ValueError caught!

try:
    with open('non_existent_file.txt') as f:
        print(f.read())
except FileNotFoundError:
    print("FileNotFoundError caught!")

# Expected output: FileNotFoundError caught!

Remember, practice is key to mastering Python exceptions. Keep experimenting with different scenarios to get a firm grip on the topic!