very cool

How could you submit it, even though it fails for a negative first array?

damn two liners always looks good!!

This has higher complexity. It sorts the list, so complexity is O(n log n), whereas if you use collections.Counter (a dict) it's (amortized) O(n), which is faster

Thank you! That's damn smart.

It checks if there is not a None inside the tuple (a1, a2) and return True if there is not and False if there is. Its just like (a1 != None and a2 != None)

could you explain the 'None not in'? Im not sure I fully grasp that.

this solution seems to break in one of my tests.

a1 = [121,None,144, 19,161,19,144,19,11]
a2 = [11 * 11, 121 * 121, 144 * 144, 19 * 19, 161 * 161, 19 * 19, 144 * 144, 19 * 19]
self.assertFalse(comp(a1,a2))

and

a1 = [121,144, 19,161,19,144,19,11]
a2 = [11 * 11, None]
self.assertFalse(comp(a1,a2))

This is so nice and clean.