Python 3: Handling Errors Apr 2026

: Pythonic code often follows "Easier to Ask Forgiveness than Permission" (EAFP)—trying an operation and handling the failure rather than checking if it's possible beforehand. Common Built-in Exceptions

: Use the raise keyword to manually trigger an exception when a specific condition isn't met.

: Runs only if the code in the try block executed without any exceptions. Use this for code that should only run if the "risky" part succeeded. Python 3: Handling errors

: For domain-specific logic, you can define your own error classes by inheriting from the built-in Exception class.

try: number = int(input("Enter a number: ")) result = 10 / number except ValueError: print("Error: Please enter a valid integer.") except ZeroDivisionError: print("Error: Cannot divide by zero.") Use code with caution. Copied to clipboard Expanding Control: else and finally : Pythonic code often follows "Easier to Ask

: Avoid using a bare except: or except Exception: . Catching specific errors (e.g., FileNotFoundError ) prevents you from accidentally silencing unexpected bugs you didn't intend to handle.

: Contains the code that executes if a specific error occurs. Use this for code that should only run

: Always runs regardless of whether an error occurred. This is essential for resource cleanup , such as closing files or database connections. Strategic Techniques