tictactoe

test_tictactoe.py

import unittest

from tictac import (
    Board, IllegalMoveError, WrongTurnError,
    IN_PROGRESS, X_WON, O_WON, DRAW)


class TestBoard(unittest.TestCase):
    def setUp(self):
        self.board = Board()

    def test_size(self):
        self.assertEqual(self.board.width, 3)
        self.assertEqual(self.board.height, 3)

    def test_make_a_move(self):
        self.board["A1"] = 'X'
        self.assertEqual(self.board['A1'], 'X')

    def test_make_an_invalid_move(self):
        with self.assertRaises(IndexError):
            self.board["Щ5"] = 'X'

        with self.assertRaises(IndexError):
            self.board["A42"] = 'O'

    def test_misunderstood_move(self):
        with self.assertRaises(IndexError):
            self.board["A12"] = 'X'

        self.assertEqual(self.board['A1'], ' ')

    def test_change_move(self):
        self.board['A1'] = 'X'

        with self.assertRaises(IllegalMoveError):
            self.board['A1'] = 'O'

    def test_place_illegal_chars(self):
        with self.assertRaises(IllegalMoveError):
            self.board['A1'] = 'Щ'

    def test_two_moves_by_the_same_player(self):
        self.board['A1'] = 'X'
        with self.assertRaises(WrongTurnError):
            self.board['A2'] = 'X'

    def test_game_state_in_progress(self):
        self.assertEqual(self.board.state, IN_PROGRESS)

    def test_game_x_won(self):
        self.board._Board__grid = [
            ['X', 'X', 'X'],
            ['O', 'O', ' '],
            [' ', ' ', ' '],
        ]
        self.assertEqual(self.board.state, X_WON)
        self.board._Board__grid = [
            ['X', 'O', 'O'],
            ['X', ' ', ' '],
            ['X', ' ', ' '],
        ]
        self.assertEqual(self.board.state, X_WON)
        self.board._Board__grid = [
            ['X', 'O', 'O'],
            [' ', 'X', ' '],
            [' ', ' ', 'X'],
        ]
        self.assertEqual(self.board.state, X_WON)

    def test_game_o_won(self):
        self.board._Board__grid = [
            ['O', 'O', 'O'],
            ['X', 'X', ' '],
            [' ', ' ', ' '],
        ]
        self.assertEqual(self.board.state, O_WON)
        self.board._Board__grid = [
            ['O', 'X', 'X'],
            ['O', ' ', ' '],
            ['O', ' ', ' '],
        ]
        self.assertEqual(self.board.state, O_WON)
        self.board._Board__grid = [
            ['O', 'X', 'X'],
            [' ', 'O', ' '],
            [' ', ' ', 'O'],
        ]
        self.assertEqual(self.board.state, O_WON)

    def test_draw(self):
        self.board._Board__grid = [
            ['O', 'X', 'X'],
            ['X', 'X', 'O'],
            ['O', 'O', 'X'],
        ]
        self.assertEqual(self.board.state, DRAW)

    def test_move_on_ended_game(self):
        self.board._Board__grid = [
            ['O', 'X', 'X'],
            [' ', 'O', ' '],
            [' ', ' ', 'O'],
        ]

        with self.assertRaises(IllegalMoveError):
            self.board['B1'] = 'X'


if __name__ == '__main__':
    unittest.main()

tictactoe.py

from copy import deepcopy

X = 'X'
O = 'O'
IN_PROGRESS = 0
X_WON = 1
O_WON = 2
DRAW = 3


class Board:
    width = 3
    height = 3

    def __init__(self):
        self._on_turn = X
        self.__grid = [
            [' ', ' ', ' '],
            [' ', ' ', ' '],
            [' ', ' ', ' '],
        ]

    @property
    def state(self):
        lines = deepcopy(self.__grid)
        columns = zip(*self.__grid)
        diagonals = (((0, 0), (1, 1), (2, 2)),
                     ((0, 2), (1, 1), (2, 0)))
        for diagonal in diagonals:
            lines.append([self.__grid[x][y] for x, y in diagonal])
        lines.extend(columns)
        for line in lines:
            if set(line) == {X}:
                return X_WON
            elif set(line) == {O}:
                return O_WON

        if not any(map(lambda line: ' ' in line, self.__grid)):
            return DRAW

        return IN_PROGRESS

    def _convert_to_coords(self, key):
        if any([len(key) != 2,
               key[0] not in {'A', 'B', 'C'},
               int(key[1]) not in {1, 2, 3}]):
            raise IndexError
        return ord(key[0]) - ord('A'), int(key[1]) - 1

    def __setitem__(self, key, value):
        if self.state != IN_PROGRESS:
            raise IllegalMoveError("Game over")
        x, y = self._convert_to_coords(key)
        if self.__grid[x][y] != ' ':
            raise IllegalMoveError("You can't change moves!")

        if value not in {X, O}:
            raise IllegalMoveError("You must place X or O")

        if value != self._on_turn:
            raise WrongTurnError("{} is on turn".format(self._on_turn))
        self._on_turn = X if self._on_turn == O else O

        self.__grid[x][y] = value

    def __getitem__(self, key):
        x, y = self._convert_to_coords(key)
        return self.__grid[x][y]


class IllegalMoveError(Exception):
    pass


class WrongTurnError(Exception):
    pass