In our example, Python offers two ways to access the exception information. For both, the Python script first must have import sys before the try: .. except: portion of the code. With the first method ...

Python objects are “reference counted.” ... such as exception handling. External modules can be divided into those that are platform-specific and those that are cross-platform.

Exceptions always inherit from Exception. Usually they are empty classes. Use pass for the body. You can also make a hierarchy of your exceptions. It is often good practice for libraries to define ...

It is an object derived from an Exception class, though it does not follow the behavior. Calling it an Exception is purely semantics at this point, but I see nothing wrong with not throwing it.