Exception Handling Flashcards

What is the correct way to define a custom exception that carries an error code?

Answer: class MyError(Exception): def __init__(self, msg, code): super().__init__(msg) self.code = code

Subclass `Exception`, call `super().__init__()` with the message, and store extra attributes like `code` as instance variables.

What does `sys.exc_info()` return when called outside of an exception handler?

Answer: (None, None, None)

Outside an active exception handler, `sys.exc_info()` returns `(None, None, None)` indicating no exception is being handled.

Which module provides `contextmanager` decorator for creating context managers that handle exceptions?

Answer: contextlib

`contextlib.contextmanager` lets you write a generator-based context manager where code before `yield` is setup and code after `yield` (with try/except) handles teardown and exceptions.

In a `try/except/else/finally` block, what is the correct execution order when no exception is raised?

Answer: try → else → finally

When no exception occurs: `try` runs, `except` is skipped, `else` runs, then `finally` always runs last.

What does the `__traceback__` attribute of an exception object contain?

Answer: A traceback object representing the call stack at the time of the exception

`__traceback__` holds a traceback object that can be inspected or passed to `traceback.print_tb()` to display the call stack.

What is the safest way to log an exception with its full traceback using the `logging` module?

Answer: logging.exception('message')

`logging.exception()` automatically appends the current exception's traceback to the log message when called inside an `except` block.

Which exception is raised when an `await` expression is used outside an `async` function?

Answer: SyntaxError

Using `await` outside an `async def` function is a `SyntaxError` caught at compile time, not at runtime.