A player is a tic-tac-toe participant represented by the marker X or O. The marker identifies who occupies each board cell and whose turn is being processed. section 21.1 section 22.1
A player participates in the game by:
- Providing X or O alongside a selected cell to apply a move. section 21.1.2
- Taking turns, with invalid moves leaving the current player unchanged. section 22.1
- Appearing in the rendered board and winner announcement. section 22.1
if any([args.player, args.cell]) and not all([args.player, args.cell]):
parser.error('Must provide both --player and --cell')
Require both the player marker and cell when applying a command-line move. section 21.2.1
A player takes a turn
The X player selects cell 1; the board displays X, and the prompt switches to O. Selecting occupied cell 1 again leaves O as the current player. section 22.1
