Type Annotations

Type annotations are somewhat similar to value annotations, although they operate on types insted of individual values or objects. They can be used to check the presence, or lack thereof, of objects of a specific type in a memory footprint, or conditions on that presence.

Forbid Type

The ForbidType annotation asserts that a student’s memory footprint has no values of a specific type in it. For example, if students should be implementing an algorithm without vectorization, it is possible to create an annotation forbidding the use of arrays:

import numpy as np

pybryt.ForbidType(np.ndarray, failure_message="Arrays are not allowed!")

Checking for values is performed using Python’s built-in isinstance function. Types passed to the constructor must be pickleable with the dill library.