Improve error handling with try/except (no logic change)

[yjxuestc0919]

The previous script will directly exit the course-grabbing script under certain error conditions (such as server rate limitations or error situations, etc.), thus failing to achieve the effect of continuous monitoring and course-grabbing. This PR improves the program's robustness by adding try/except blocks around potential failure points and NOT change the basic logic.

• Prevents unexpected crashes.

• Ensures the program continues running when minor errors occur.

• No changes were made to the core business logic or output.