Developers' Forum

That line is mostly a fossil from earlier days. I originally used it in the documentation to illustrate that question authors could treat the student answer as a string variable and perform simple extra checks using it. For example, even without customising the question they might write test code like, 

if 'break' in __student_answer__:
    print("Your answer is not allowed to use 'break' statements")
else:
    print(some_student_func(...)) # The normal test

Nowadays such test code usually goes in the template itself, or in the prototype, or in TEST.extra or GLOBAL_EXTRA fields. And in any case such tests are better done by parsing the student answer properly (if a parser is available) rather than with a simple string test.

I left the line in the template thinking it might help authors to realise what could be done, but reading your post I now realise it's probably confusing rather than helping. But ... if I remove it from the existing python3 and python2 prototypes I'll break any questions using it in the originally-intended manner. I wonder if any/many question authors are using it? Comments, anyone?