Proper way to declare custom exceptions in modern Python

Custom exceptions in Python allow you to create specific error types tailored to your application's needs. They are especially useful when you want to differentiate between various error situations or provide more meaningful error messages to users. In this tutorial, we'll walk you through the proper way to declare custom exceptions in modern Python with code examples.
To create a custom exception, you need to define a new exception class. In Python, custom exceptions should inherit from the built-in Exception class or one of its subclasses like BaseException. Here's how you can create a custom exception class:
In this example, we create a custom exception class named MyCustomException. It inherits from the base Exception class and has an optional message parameter in the constructor. The __init__ method sets the error message and calls the parent constructor.
Once you've defined your custom exception, you can use it in your code to raise and handle errors as needed. Here's how you can raise your custom exception:
In this example, if the some_error_condition is met, we raise our custom exception with a specific error message.
You can catch and handle custom exceptions using try and except blocks. Here's an example:
In this code, we try to execute some_function(), and if a