Write a context manager in Python
Python interview exercise on Errors & Context Managers, difficulty 3 of 3. Solve it in the editor beside a worked example, or cold in Interview mode with the example hidden; the tests run the moment you do.
Write Recorder(log) as a class with __enter__ and __exit__. Entering appends "enter" and returns the recorder; leaving appends "exit". If the body raised, it first appends "error:<ExceptionName>", and it lets the exception continue to the caller.
Each exercise pairs a worked example with a twin problem to solve in a real editor; the tests run the moment you do. Interview mode hides the example: solve it from memory, without the hint or the solution, and it counts as solved cold. Progress is saved in your browser, and in your account if you sign in.