How to solve a Sudoku puzzle in Python

• Download and run the Python file here.
  You will need to have Python and Pygame installed.
• To solve a particular puzzle change the values of "digits".
  NB Solved valus need to be in square brackets and blank spaces need to be ''
  And watch out for typos.
• You can make it run quicker or slower by changing the values in the lines:
  pygame.time.wait(10)

It works for most Sudoku puzzles but not the very hardest.