Simple code golfing Sudoku solver in Python

A while ago (back in 2015) I decided to try to code golf a Sudoku solver in Python. This is the result.

The sudoku.py file is partially minimized (short variable names) but with some comments and spacing. While sudoku_min.py is minified by hand, for now. Example runs:

$ python sudoku.py 123456789456789123789123456000000000000000000000000000000000000000000000000000000
123456789456789123789123456214365897365897214897214365531642978642978531978531642

# This one takes quite a while for my solver, almost a minute using a recent PyPy
$ python sudoku.py 850002400720000009004000000000107002305000900040000000000080070017000000000036040
859612437723854169164379528986147352375268914241593786432981675617425893598736241

and it prints the solution it found.

Size

As of when this README was last updated, the minified version is 375 bytes. The smallest I could find is 169 bytes at ShortestSudokuSolver. But I’m still fairly happy with it overall.

Read more

I wrote up a small blog post about this as well.

Author

Byron Peebles, 2015–2021.