Check your understanding: partial functions and methods

Review

1. What does functools.partial() return?

   Creating a partial object stores a callable and argument configuration. The underlying function runs when the partial object is called.
2. Where do additional positional arguments go when a partial object is called?

   Stored positional arguments are prepended to the new positional arguments. Without a placeholder, partial() does not reserve a positional hole.
3. A partial object stores prefix="Draft: ". What happens if the caller supplies prefix="Final: "?

   New keyword arguments extend or override the stored keyword mapping for that call.
4. Why is partial(round, ndigits=1) suitable for map(rounding, values)?

   map() passes one item at a time to the callback. The partial supplies the other option to round() so each call needs only the item.
5. Which statement correctly distinguishes partial() from function-result caching?

   Partial application changes how calls are configured. functools.cache and lru_cache remember results, subject to their key and lifecycle behavior.
6. What makes functools.partialmethod() appropriate for defining a configured method on a class?

   partialmethod is a descriptor intended for method definitions. It keeps normal instance binding and supplies the configured arguments to the underlying callable.