What is exception chaining in Python?

Exception chaining in Python refers to the practice of raising a new exception while already handling another exception. This mechanism is particularly useful for maintaining the context of errors, allowing developers to understand not only that an error occurred but also the circumstances under which it arose.

When an exception is caught and another one is raised during the handling of that initial exception, Python allows the original exception to be linked to the new exception. This creates a chain that shows both the original issue and the new problem that arose while trying to solve it. The traceback will typically show both exceptions, providing clear visibility into the sequence of events that led to the current error.

This approach enhances debugging as it preserves the information about the first exception, making it easier for developers to identify the root cause of the error and understand how it progressed to the current situation. Thus, correctly understanding and utilizing exception chaining is vital for effective error handling in Python programming.