Fix bug in python comparison.

Fix bug in python comparison.

It worked in python2 but not the way the authors imagined. Because hex always returns a string.

From python2:
>>> 1 > "2"
False
>>> "2" > 1
True
>>> "1" > 2
True

The rational is that an integer is always smaller than a string.

In python 3 this because it does not make sense to compare objects of different types.