xudoku - Solve sudoku using an 'exact cover' algorithm

This is the sudoku code from @moygit's project 'exact_cover_np'.

The package is maintained by me, @jwg4.

I separated the code for the 'exact cover' algorithm (now available at https://github.com/jwg4/exact_cover) from the sudoku code and created this package. At that package you can find more info about the exact cover algorithm, which can be used for lots of combinatoric problems.

How to use the package

>>> import xudoku
>>> s = xudoku.Sudoku(9)
>>> s.read("tests/files/insight.csv")
>>> sol = s.solve()
>>> sol._sudo.tolist()
[[1, 3, 5, 2, 9, 7, 8, 6, 4], [9, 8, 2, 4, 1, 6, 7, 5, 3], [7, 6, 4, 3, 8, 5, 1, 9, 2], [2, 1, 8, 7, 3, 9, 6, 4, 5], [5, 9, 7, 8, 6, 4, 2, 3, 1], [6, 4, 3, 1, 5, 2, 9, 7, 8], [4, 2, 6, 5, 7, 1, 3, 8, 9], [3, 5, 9, 6, 2, 8, 4, 1, 7], [8, 7, 1, 9, 4, 3, 5, 2, 6]]
>>> s._hardness
'Easy'

Currently the puzzle data can only be read from CSV. You could use io.StringIO, which turns a string into a file-like object, if you want to generate your sudoku puzzle in code.