I didn't write the Python version, but your answer seems to solve it in the spirit of the original.

The purpose of this test is basically to find a way to cheat :p

Is this marked as a question because you want the author to answer specifically? I don't know why people haven't solved it in the same way as you.

This criticism is very helpful.

http://stackoverflow.com/questions/600293/how-to-check-if-a-number-is-a-power-of-2

Which examples highlight that your tests are going to try to set the attributes directly?

I'm getting no method error for "complete!" and "complete?" which don't seem to be defined in example tests?

The 'standard' modern form is, to my understanding, essentially a decimal system so it typically treats each digit of the number individually, which means 1990 is treated as 1000 + 900 + 90 + 0(ignored) as the author has indicated.

Further abbreviations are possible, sure, but I've seen no source that would indicate that they're widely accepted (unless you count Microsoft Excel's fairly unique willingness to display all sorts of weird variants). Do you have a source which suggests that Roman numerals correctly use the shortest possible variant? This would surprise me, given that the original numeric system was even more verbose than our modern one, with subtractive notation being infrequently used, leading to long strings of additive symbols to represent large numbers.

Description fails to prepare users for numerical usernames or for being passed duplicate usernames with marks that don't match. Why should I favour [1,2] over [1,3].

Why should dataclean([['a',5],['b',3],['a',5]]) be [['b',3],['a',5]] while dataclean([['a',2],['b',3],['a',2]]) returns [['a',2],['b',3]] in a different order?

@obrok Test framework should no longer impact Kernel patches so it's safe to put eval disable back in.

Doesn't seem to specify that attributes need to be read/write for Ruby.

It seems like you are now checking for this but don't mention it in your spec?

Should the Ball class be available to my test cases in Ruby? I can't use your predefined tests because Ball is not defined.

Am I misunderstanding your comment?

"returns the remainder after dividing the larger number by the smaller number" is part of the description.