Variable are not shared across test cell in Python notebooks

[joelostblom]

In R, defining a variable in one test cell will make it available to all other test cells for that question. In Python, the variable needs to be assigned in each test cells, which means performing the same (potentially expensive) computation multiple times. It would be great if Python test would be consistent with how Otter works for R tests and share namespace for variables.

Versions
Otter 3.1.4
Python 3.9.7

[chrispyles]

For Python, this is intentional. We don't want tests to clutter the student's global environment, so we duplicate it before running any tests on it. The only reason this behavior is present in R is because we haven't yet found a way of running the tests correctly without running them directly in the student's environment. We would like to standardize the behavior, but the goal would be to make R like Python, not Python like R.

[joelostblom]

Thanks for the reply! It makes sense to restrict the test cells from cluttering the students environments. I think it would still be quite useful to be able to create test constants (both individual values and functions) that would be accessible to all tests for that particular question, would you consider adding a way to define these, e.g.

Test cell 1

# BEGIN TEST CONSTANT
def some_long_function_def(student_obj):
    return ...
# END TEST CONSTANT
test_cont = expensive_computation(student_obj)  # TEST CONSTANT

assert test_const['value1']
assert some_long_function_def(test_const['value1'])

Test cell 2

assert some_long_function_def(test_const['value2'])

The reason for not having both asserts in the same cell would be to be able to give partial points if one of them is correct.

[joelostblom]

I believe it would be possible to implement the test constant idea via setting the Execution context for the doctest.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[joelostblom]

I encountered this again and wanted to check in in case there is any other way to achieve what I would like to do. Currently I'm seeing a lot of duplication code in my test, for example in this instance where the only difference is in the assert messages:

Since you mentioned above that it is unlikely that sharing of variables will be implemented in the future, maybe the best solution is to keep trying to get #536 working, since that would allows writing everything in one cell. Although I don't think that would not allow for partial points per assert statement, the points are just split per test cell and not per assert, right?