Python Error Handling

Python error handling

Created By: chatGPT

In Python, error handling is crucial for creating robust applications. You can manage exceptions using the try, except, else, and finally blocks. This lets you capture and respond to errors gracefully without crashing the program.

try:
    # Code that may raise an exception
    result = 10 / 0  # This will raise a ZeroDivisionError
except ZeroDivisionError:
    print('You cannot divide by zero!')
else:
    print('Division successful. Result:', result)
finally:
    print('Execution completed.')

The try block contains the code that might throw an exception. If an exception occurs, the control will jump to the except block where you can handle the error. The else block runs if the code in try runs without any exceptions. The finally block will always execute, regardless of whether an exception was raised or not, making it ideal for cleanup actions.

try:
    # Open a file and read its content
    with open('sample.txt', 'r') as file:
        data = file.read()
except FileNotFoundError:
    print('File not found!')
else:
    print('File content:', data)
finally:
    print('Finished attempting to read the file.')

You can also catch multiple exceptions together or use an as clause to access the exception object. This allows you to inspect the error for more in-depth debugging.

try:
    # Code that may raise different exceptions
    value = int('string')  # Raises ValueError
    result = 10 / 0  # Raises ZeroDivisionError
except (ValueError, ZeroDivisionError) as e:
    print('An error occurred:', e)
else:
    print('Operation successful:', result)
finally:
    print('Error handling complete.')

Using custom exceptions can improve the error handling process. This involves creating your own exception classes by extending the built-in Exception class, which allows you to raise specific errors in your application.

class CustomError(Exception):
    pass

try:
    raise CustomError('This is a custom error message')
except CustomError as e:
    print('Caught a custom error:', e)

To summarize, effective error handling in Python is essential to avoid unexpected application crashes. By using try, except, else, and finally, along with custom exceptions when needed, you can ensure that your applications can handle errors gracefully and remain user-friendly.

try:
    risky_operation()
except Exception as e:
    logger.error('An error occurred:', exc_info=True)
    print('Error handled.')  # Graceful handling