Error Handling and Debugging Flashcards

What does the `traceback` module help with in Python?

Answer: Formatting and printing stack trace information

The `traceback` module provides utilities for extracting, formatting, and printing Python stack traces for debugging purposes.

What is the difference between `except Exception` and `except BaseException`?

Answer: `except BaseException` also catches SystemExit and KeyboardInterrupt

`BaseException` is the root of all exceptions, so `except BaseException` also catches `SystemExit`, `KeyboardInterrupt`, and `GeneratorExit`, which `except Exception` does not.

Which of the following will raise an `IndexError`?

Answer: my_list = [1, 2]; my_list[5]

Accessing `my_list[5]` on a list with only 2 elements raises `IndexError` because the index is out of the valid range.

What is the output of the following? x = [1, 2, 3] try: print(x[10]) except (IndexError, TypeError) as e: print(type(e).__name__)

Answer: IndexError

Accessing index 10 on a 3-element list raises `IndexError`, and `type(e).__name__` returns the string 'IndexError'.

When is the `else` clause of a try/except structure executed?

Answer: When no exception is raised in the try block

The `else` clause executes only when the `try` block completes without raising any exception.

What is the correct way to raise a ValueError with a custom message?

Answer: raise ValueError('message')

Exceptions are raised by calling them like a class constructor: `raise ValueError('message')` creates an instance and raises it.

What will this code print? try: raise ValueError('oops') finally: print('done')

Answer: done, then the exception propagates

The `finally` block runs and prints 'done' before the unhandled `ValueError` propagates up and terminates the program.