Error Handling

Key Concepts

• Python try except: Allows you to catch and handle errors.
• Python finally: Executes regardless of whether an error is raised or not.
• Custom exceptions: Define your own exceptions to handle specific errors.

Practical Steps

• Use the try-except block: Wrap potentially error-prone code inside a try block and handle errors in the except block.
• Catch specific errors: Use specific except clauses to catch particular types of errors, e.g., except ValueError, except IndexError.
• Handle general errors: Use the general except clause to catch any unexpected error, e.g., except Exception.
• Use the finally block: Execute code that should always run, regardless of errors, e.g., closing files, releasing resources.
• Raise custom exceptions: Define custom exceptions using the raise keyword to handle specific scenarios.

Example

try:
    # potentially error-prone code
    result = int(input("Enter a number: "))
except ValueError:
    print("Invalid input. Please enter an integer.")
finally:
    # cleanup code
    print("Exiting program.")

Improved Guide

Error Handling in Python (Simplified)

Key Concepts

• Try and Except: Catch and handle errors.
• Finally: Do stuff after trying.
• Custom Errors: Make your own errors.

Steps

Try and Catch:

• Try: Run code that might fail.
• Except: Catch errors if they happen.

Finally:

• Do stuff always, even if there's an error.

Custom Errors:

• Make your own errors using raise.

Example

try:
    age = int(input("How old are you?"))
except ValueError:
    print("Invalid input. Please enter a number.")
finally:
    print("Thank you for participating.")