Fractions bigger than 1 are arbitrarily False inputs. By specifying positive for num and den, you achieve two things: you exclude arbitrarily False inputs for fractions less than 0 ( which is just as arbitrary as bigger than 1 ), and you exclude 0 as an input.

Inputs bigger than 1 are a senseless special case, as you can see in everybody's solution. You might as well exclude them.

Inputs equal to 0 are excluded for no good reason. You might as well not exclude them.

Your function must return None if q does not represent a rational number (i.e. if the last element is 0).

what's the point? This brings nothing interesting to your kata, you should just drop those inputs.

It would be nice to have some information on the inputs (ie. how large can n be? etc.)

Why q is not given as Fraction rather than list? (you can't have 1/0 (but that is pointless to test anyway))