Need help with one_hot encoding

It looks like you must have hacked on that test cell in a way that broke it. The function one_hot_matrix_test takes a function as its argument, but you have passed it the invocation of a function. It should not be necessary to change any of the test cells. When the tests fail, the right strategy is not to change the tests, but to figure out why your code fails the test. :nerd_face: Although it looks to me as if your actual function code is correct.

You can get a clean copy of the notebook and use that to restore the test code to its original state.