The functions files aren't technically standalone Python programs, and refer to things from the Python template. Thus, they can't be linted cleanly by standard Python linters. At least some of this can be avoided if the functions don't refer to, say assert_eq, directly by name, and instead retrieve the function via the globals() feature: ~~~python assert_eq = globals()["assert_eq"] ~~~ This is ugly and tedious, but arguably worth it to benefit from other checks made by standard linters.