Sudoku Game in Python

Rules of the Road

Note: The phrase 'single$-$digit numbers' will be used throughout this project to refer to numbers $1-9,$ inclusive. For the purposes of this project, we will not consider $0$ a single$-$digit number.

A Sudoku is a puzzle consisting of a $99$ grid which is partially filled with single$-$digit numbers. The objective is to fill in the rest of the grid with single$-$digit numbers so that certain rules are satisfied:

In each of the nine rows of the board, no digit is repeated $($and each digit occurs once$).$

In each of the nine columns of the board, no digit is repeated $($and each digit occurs once$).$

In each of the nine $33$ outlined 'boxes' of the board, no digit is repeated $($and each digit occurs once$).$

Example Sudoku boards. When the board satisfies the above rules and each cell is filled, it is solved.