string_digits problem

[pjritee]

If I leave out the return I get

----------------------------------------
None is not an instance of <class 'str'>
----------------------------------------

that could be fixed in this case by checking for a return but lets say the student wrote

return int(result)

then it would be

42 is not an instance of <class 'str'>

Could we do better?

[sapi]

The name of that test is 'get_digits returns a string'

I think in that context, the error message is sufficiently descriptive.

[jgat]

+1. There's also the obvious learning benefit of having students familiarise themselves with trying to read slightly-unusual error messages.