Get Started with Python Exceptions – The Ultimate Beginner's Guide (with Examples)

Python Exceptions: The Ultimate Beginner's Guide (with Examples)

Python exceptions are errors that occur during the execution of a program. They are the result of an attempted operation that failed because something went wrong. Exceptions provide a way to respond to errors, while also avoiding crashing the program. It allows developers to handle the errors more effectively and continue the execution of the program. In this guide, we will discuss the basics of Python exceptions, including what they are, when they might be generated, and how to handle them.

What are Python Exceptions?

Python exceptions are errors that arise during the execution of a program. A common example of an exception is a syntax error, which results from incorrect code. Other types of exceptions include runtime errors, arithmetical errors, and logical errors. Exceptions allow a program to detect and respond to errors without crashing. When an exception is encountered, the program will display an error message with information about the cause of the exception.

When are Python Exceptions Generated?

Exceptions are generated when the program encounters an unexpected situation or a problem. This can happen due to incorrect user input, code bugs, or program failures. For example, if a user enters a string when the program expects a number, a ValueError exception will be generated. In addition, when a file cannot be found, an IOError exception is generated.

How to Handle Python Exceptions

In Python, exception handling is done using try and except statements. The try statement allows you to test for errors and the except statement tells the program how to respond to the error. It is important to note that the except statement must come after the try statement. You can also include an else clause which will execute when no exceptions are encountered. Finally, the finally clause is executed regardless of whether an exception is encountered or not.

For example, in this code snippet, the try statement checks whether the user has entered a valid number. If the input is not a number, the except statement will catch the exception and print an error message.

try:
    num = int(input('Please enter a number: '))
except ValueError:
    print('Error: You entered an invalid number!')

Conclusion

Python exceptions are part of the language's error handling mechanism and are used to avoid program crashes. Exceptions are generated when the program encounters an unexpected situation or a problem. In Python, exception handling is done using try and except statements. With this knowledge, you should now be able to handle Python exceptions properly and prevent your program from crashing.