When is the code within the 'except' block executed?

The code within the 'except' block is executed when an expected exception is raised in the try block. This is a key aspect of error handling in programming, particularly in languages like Python. When a section of code that may raise an exception is enclosed within a try block, the program will attempt to run that code. If an exception occurs during this execution, control is immediately passed to the corresponding except block, where the error can be handled appropriately.

This mechanism allows developers to anticipate potential errors and define specific responses to handle those situations gracefully, rather than allowing the program to crash. This is particularly important for maintaining robustness in applications, as it provides a way to manage unexpected conditions without disrupting the user experience.

In contrast, a syntax error occurs before the program is run and would prevent the execution of any code altogether. If the code in the try block executes without errors, it completes normally, and the code within the except block is skipped. Lastly, the program being first run does not trigger the except block; it is specifically the raising of an exception within the try block that does so.