[avgcorrection]

> Oh, good, heavyweight error handling just in time for py3.11's zero-cost exception happy path.

I don’t get it. Languages that use exceptions for all kinds of errors will also use exceptions for routine errors that happen as a matter of course—the happy path is not the overwhelmingly most common branch, and errors are not exceptional. In turn not zero-cost for all but the exceptional case.

[klyrs]

The solution to this is to not use exceptions except for actual errors, unless it's going to be amortized away. For example, objects which have a heavy parameter, which gets memoized. With the zero-cost happy path, you only raise the exception once, when you're doing the costly thing, and subsequent accesses are free.