What happens when an error occurs inside a try block?

When an error occurs inside a try block, the except block is executed. This mechanism is a fundamental part of error handling in Python. The purpose of the try-except construct is to allow the developer to anticipate potential errors during the execution of a block of code and to define specific responses to those errors when they occur.

When an exception is raised in the try block, Python immediately stops executing the code in that block and looks for a matching exception handler in the following except block. If a suitable handler is found, the code within that except block is run, allowing the program to deal with the error gracefully instead of terminating abruptly. This approach enhances the robustness of the program, making it easier to manage errors and maintain a good user experience.

In contrast, if there is no except block or if none of the except blocks match the raised exception, Python will continue to propagate the error up the call stack, which may eventually lead to a program crash if unhandled. Thus, the execution flow is designed to respond to the error, rather than ignoring it or crashing outright.