A sudoku solver

Suds is a simple sudoku solver. It doesn't aim to be the fastest or best. Don't expect it to be able to solve anything but the easiest sudokus. Suds really exists for me to play around with Python, how to setup the infrastructure around a Python application, and so forth. It's a playground for me to learn rather than a best of breed solver.

git clone git@github.com:abadger/suds.git
cd suds
python -m suds FILENAME.json

FILENAME.json contains a json data structure with a sudoku board. It should look something like this:

{"board":
    {"rows":
        [
            [0, 0, 7, 0, 0, 0, 0, 0, 6],
            [0, 6, 0, 8, 0, 0, 2, 0, 5],
            [0, 0, 8, 0, 6, 9, 3, 0, 0],
            [7, 0, 6, 0, 3, 8, 1, 0, 0],
            [4, 8, 9, 0, 1, 0, 7, 6, 3],
            [0, 0, 3, 9, 7, 0, 5, 0, 8],
            [0, 0, 5, 6, 8, 0, 4, 0, 0],
            [8, 0, 4, 0, 0, 7, 0, 5, 0],
            [6, 0, 0, 0, 0, 0, 9, 0, 0]
        ]
    }
}

If suds is able to solve the Sudoku puzzle, it will print out the solution and exit with code 0:

The solution is:

3 4 7 5 2 1 8 9 6
9 6 1 8 4 3 2 7 5
5 2 8 7 6 9 3 1 4
7 5 6 4 3 8 1 2 9
4 8 9 2 1 5 7 6 3
2 1 3 9 7 6 5 4 8
1 9 5 6 8 2 4 3 7
8 3 4 1 9 7 6 5 2
6 7 2 3 5 4 9 8 1

If it can't, it will print a message and as much of the board as it was able to fill in. In this case, its exit code will be 1.