Sudoku Maker

Author:Ralf Schlatterbeck <>

Sudoku Maker is a generator for Sudoku number puzzles. It uses a genetic algorithm internally, so it can serve as an introduction to genetic algorithms. The generated Sudokus are usually very hard to solve -- good for getting rid of a Sudoku addiction (or maybe not).

It also includes a simple depth-first solver for sudoku puzzles -- the solver is internally needed when generating sudoku puzzles. The included can be called and reads a sudoku from standard input. It outputs the solution (if any) or if there isn't a single solution to the given puzzle it will output several (up to a maximum).

The representation of sudoku puzzles is a simple: 9 lines with 9 numbers in each line, e.g.,


The numbers 1-9 represent the given numbers of the puzzle while the zeros represent the empty tiles. A solved puzzle simply contains no zeros.

There are two variants of sudoku puzzles supported. The first variant adds the diagonals (so in each of the two diagonals the numbers 1-9 must be present), this variant can be requested with the --diagonal option. The sudoku maker currently doesn't support the variants. The second variant requires that in each quadrant there are 9 distinct colors, the same color is always at the same position in each quadrant. The numbers 1-9 must be present on each of the colors.

Sudoku puzzles can be pretty-printed as LaTeX using the included sudoku_as_tex program. This currently supports printing the diagonals in yellow if the --diagonal option is given. Color printing for the second variant of sudoku puzzles is not yet supported.

For the genetic algorithm library, my python wrapper pgapy of the parallel genetic algorithm library (pgapack) is needed. There is currently no Windows support for pgapy as it requires the pgapack library to be installed. For a skilled person it should be possible to get pgapack running on Windows, so if you're doing this, let me know.

Version 0.4: Packaging fixes

Fix package name again, stick to sudokumaker to avoid name collisions.

  • Package namespace is now sudokumaker again
  • Sudokumaker depends on

Version 0.3: Color, Diagonal

Now color constrained and diagonality constrained sudokus are supported.

  • Diagonality constrained sudokus must have the digits 1-9 in the diagonals, too. When printing, diagonals are printed in yellow.
  • Color constrained sudokus have 9 additional colors which are in the same position in every quadrant. These must have the digits 1-9, too. When printing we chose 9 different light colors.

Version 0.2: README update

The README (and the SF homepage which is generated from it) had wrong link to the project. Also the python package index didn't accept one of my classifier. Grmpf.

  • Fix project link in README (SF Logo)
  • Remove one classifier not accepted by pypi

Version 0.1: Initial Release

Sudoku Maker is a generator for Sudoku number puzzles. It uses a genetic algorithm internally.

  • First Release after a long silent development