Error Handling

Learning Objectives Define what an exception is and why it occurs in a program. Use the `try` and `except` blocks to prevent a program from crashing due to common errors. Handle specific types of exceptions, such as `ValueError` and `IndexError`. Implement the `else` block to run code only when no errors occur. Use the `finally` block to execute essential cleanup code, regardless of whether an error happened. Write robust programs that can handle invalid user input and other unexpected situations gracefully. Ever used an app that crashed when you typed something weird? 💥 Let's learn how to build smarter programs that handle surprises instead of breaking! This lesson teaches you how to anticipate and manage errors in your Python code. You'll learn a powerful techn...

TermDefinitionExample ExceptionAn error that happens while a program is running. It's Python's way of saying 'I don't know what to do!' and stopping everything.If you try to convert the word 'hello' into a number, Python raises a `ValueError` exception. try blockA block of code where you put 'risky' operations that might cause an exception.`try: age = int(input('Enter your age: '))` is risky because the user might not type a number. except blockA block of code that runs ONLY if an exception occurs in the `try` block. It's your program's 'Plan B'.`except ValueError: print('That was not a valid number!')` catches the specific error and prints a friendly message. else blockAn optional block of code that runs...

The Basic `try...except` Pattern try: # Risky code that might fail except ExceptionType: # Code to run if the specific exception happens Use this to wrap any code that could potentially crash your program. Always try to catch a specific exception (like `ValueError`) instead of a general one. The Full `try...except...else...finally` Structure try: # Risky code except: # Runs if an error occurs else: # Runs if NO error occurs finally: # ALWAYS runs, error or not This provides complete control. Use `else` for code that depends on the `try` block succeeding. Use `finally` for essential cleanup actions that must happen no matter what.