Advanced Topics

Section 5: Advanced Topics

Lesson 1: Exception Handling

1.1 Understanding Exceptions

Exceptions are events that occur during the execution of a program and disrupt the normal flow of code. Handling exceptions is crucial for gracefully managing errors and preventing program crashes.

Example: 

# Understanding exceptions

try:

    result = 10 / 0  # Attempting to divide by zero

except ZeroDivisionError as e:

    print(f"Error: {e}")

    # Output: Error: division by zero


1.2 Using try, except Blocks

The try and except blocks in Python allow you to catch and handle exceptions, preventing them from causing the program to terminate abruptly.

Example: 

# Using try, except blocks

def divide_numbers(a, b):

    try:

        result = a / b

        return result

    except ZeroDivisionError as e:

        print(f"Error: {e}")

        return None


result1 = divide_numbers(10, 2)    # Output: 5.0

result2 = divide_numbers(10, 0)    # Output: Error: division by zero, result2 is None


Lesson 2: Regular Expressions

2.1 Pattern Matching Using Regular Expressions

Regular expressions (regex) are powerful tools for pattern matching in strings. They provide a concise and flexible way to search, match, and manipulate text.

Example: 

# Pattern matching using regular expressions

import re


pattern = r"\b\d{3}-\d{2}-\d{4}\b"  # Match social security numbers

text = "John's SSN is 123-45-6789 and Jane's is 987-65-4321."


matches = re.findall(pattern, text)

print(matches)  # Output: ['123-45-6789', '987-65-4321']


Regular expression breakdown:


In Section 5, we explored advanced topics in Python, focusing on exception handling and regular expressions.

Exception handling is crucial for managing errors and preventing program crashes. The try and except blocks provide a mechanism to gracefully handle exceptions and continue the execution of a program.

Regular expressions offer a powerful way to perform pattern matching in strings. By defining specific patterns, you can search for, extract, or replace text efficiently. Mastering exception handling and regular expressions enhances your ability to write robust and flexible Python code, making your applications more resilient and capable of handling diverse scenarios.