Shortest Sudoku Solver in Python

Question

I started to write my own Sudoku solver in Python but it was too slow / inelegant,
so I searched for an elegant way to solve this problem.

I stumbled upon this cryptic Sudoku solver and the very good explanation given by the community: Shortest Sudoku Solver in Python - How does it work?
I have understood the explained and stretched out version but I have one problem with this:

When I run the version explained by Bill Barksdale with a Python version below 3.0 it takes pretty long to solve a Sudoku, but succeeds and prints out the right solution.
When I run the program with Python 3.0 or 3.4, the program is done in less than a second, but prints out a wrong solution.

I have tried to find the problem with Python > 3.0 but I have no idea.
Could someone please point out why this program is running below Python 3.0 but not above?

Thanks

Answer 1

I suspect that the problem may well be the difference in the Python 3 divide operator in Python 2 2/3 = 0 but in Python 3 2/3 = 0.66666 which will mess up the logic nicely. You can try adding from __future__ import division and running under Python 2 or by replacing all the / s with // and running under Python 3.

In general obfuscated code is also unmaintainable code so I would avoid describing it as elegant.