Summary

Conclusions

An exception carries information about a failed operation to a level that can make a decision. Specific handlers, short try blocks, and explicit causes preserve that information. A log explains the execution history, while a debugger shows program state at a selected point. Reference examples establish that a formula is correct; the absence of a traceback does not.

Self-check questions

1. How do syntax errors, logic errors, and runtime exceptions differ?
2. Which line should you start with when reading a traceback?
3. Why does except Exception not catch Ctrl+C?
4. How does handler order affect the result?
5. When does else run, and when does finally run?
6. What is the syntax for several types in Python 3.14, and when are parentheses needed?
7. What does args contain, and why should you avoid comparing error messages?
8. How do raise, raise error, and raise ... from error differ?
9. Why have a separate domain-error type?
10. How does except* differ from ordinary except?
11. How does add_note help locate an invalid field?
12. Which checks must not use assert?
13. When is logger.exception more useful than logger.error?
14. What hypothesis does a conditional breakpoint test?
15. How do you reproduce a PyCharm state inspection using pdb?

Useful links

• https://docs.python.org/3.14/tutorial/errors.html.
• https://docs.python.org/3.14/library/exceptions.html.
• https://docs.python.org/3.14/reference/compound_stmts.html#the-try-statement.
• https://peps.python.org/pep-0758/.
• https://docs.python.org/3.14/howto/logging.html.
• https://docs.python.org/3.14/library/pdb.html.
• https://www.jetbrains.com/help/pycharm/debugging-code.html.