Write a Python program that plays tic-tac-toe against a human player.

Your program should draw the game board, ask the user for the coordinates of the next mark, and pronounce the winner.

Note: The tic-tac-toe game is played on a 3x3 grid the game is played by two players, one of which here is the computer, who take turns. The first player marks move with a circle, the second with a cross, etc. The player who has formed a horizontal, vertical, or diagonal sequence of three marks wins.

Include comments within your program explaining what each distinct part is responsible for.