Stop Letting Python Functions Lie to You: Introducing explicit-result

Python is beautiful, readable, and highly expressive. But its built-in error handling mechanism, exceptions, has a fundamental flaw: Exceptions are invisible. Take a look at this standard Python function signature: def get_user ( user_id : int ) -> User : ... What does this signature tell you? It promises to return a User . But does it? What happens if the database connection drops? What if user_id doesn't exist? What if there's a permission issue? You can’t know without digging into the impleme