Hi there! I ran into this recently: both the sync and async Lock APIs have extend and do_extend typed as returning bool, but in practice only True is returned.

For example, here:

Instead of False, these APIs use exceptions to communicate failure states.

The current return type can lead to developer confusion, e.g. developers mistakenly doing this:

if not lock.extend(...):
    # handle lock extension failure

...which doesn't work as expected, since lock failure causes a raise LockError instead.

Proposed solution

I think the simplest solution here would be to refine the return types on these APIs: instead of -> bool these APIs could be annotated with -> typing.Literal[True] to communicate clearly to developers that there's no meaningful conditional check on the return value.

Alternatives

An alternative to the proposed solution above would be to document in redis-py's docs that the return type of bool is really just the True value, and that users must handle errors solely through exception handling. I think this would be fine, but that it would be a lot clearer to have this encoded at the type layer additionally, per above 🙂