for loop stumbling block

[perfringo]

Thanks for in interesting info perfringo , now I can lecture about leap years too

This knowledge is 'needed' in assignments because there are several sort of limitations (can't use built-in modules etc). 'Normal' way of doing it would be using built-in modules like calendar etc.

If it's a homework then there are (probably) automated tests which (probably) will use built-in modules which return correct leap years. So code will not pass if leap years are not calculated correctly. Professors also very often try to mislead students by providing test sample which seems general but actually is specific case (as with year 2000 in this example). That's why I called it 'critical thinking'. Been there, done that