Message 175953 - Python tracker

The proposed patch upgrades tests to use specialized checks added in 3.1 and 3.2 (assertIsNone(x) instead assertTrue(x is None), assertLess(a, b) instead assertTrue(a < b), etc).  This modern checks provide a more useful error message in case of a fail.

Replaced only those checks that are not related to the tested operators.  For example, assertTrue(a < b) preserved if the operator "<" is tested.