tennis.py

#!/usr/bin/python3

STARTING_SCORE = ('0', '0')

# key: previous score; value: new score if player 0 scores a point from that
POINT_LOOKUP = {
    ('0', '0'): ('15', '0'),
    ('0', '15'): ('15', '15'),
    ('0', '30'): ('15', '30'),
    ('0', '40'): ('15', '40'),
    ('15', '0'): ('30', '0'),
    ('15', '15'): ('30', '15'),
    ('15', '30'): ('30', '30'),
    ('15', '40'): ('30', '40'),
    ('30', '0'): ('40', '0'),
    ('30', '15'): ('40', '15'),
    ('30', '30'): ('40', '30'),
    ('30', '40'): ('40', '40'),
    ('40', '0'): ('WON', '0'),
    ('40', '15'): ('WON', '15'),
    ('40', '30'): ('WON', '30'),
    ('40', '40'): ('ADV', '40'),
    ('40', 'ADV'): ('40', '40'),
    ('ADV', '40'): ('WON', '40'),
    }


def score_after_point(old_score, player_who_scored):
    if player_who_scored == 0:
        return POINT_LOOKUP[old_score]
    elif player_who_scored == 1:
        reversed_old_score = tuple(reversed(old_score))
        reversed_new_score = POINT_LOOKUP[reversed_old_score]
        new_score = tuple(reversed(reversed_new_score))
        return new_score


def human_score_name(score):
    if score == ('40', '40'):
        return 'DEUCE'
    elif score[0] == 'WON':
        return 'PLAYER 0 WINS'
    elif score[1] == 'WON':
        return 'PLAYER 1 WINS'
    else:
        return '%s-%s' % score


def game_finished(score):
    return 'WON' in score


def test_player0_scored():
    assert score_after_point(('0', '0'), 0) == ('15', '0')


def test_player1_scored():
    assert score_after_point(('0', '0'), 1) == ('0', '15')


def test_deuce():
    assert human_score_name(('40', '40')) == 'DEUCE'


def test_normal_score():
    assert human_score_name(('15', '15')) == '15-15'


def test_player0_won():
    assert human_score_name(('WON', '0')) == 'PLAYER 0 WINS'


def test_player1_won():
    assert human_score_name(('0', 'WON')) == 'PLAYER 1 WINS'


def test_not_finished():
    assert not game_finished(('0', '0'))


def test_player0_finished():
    assert game_finished(('WON', '0'))


def test_player1_finished():
    assert game_finished(('0', 'WON'))


if __name__ == '__main__':
    score = STARTING_SCORE
    while not game_finished(score):
        print("Score: %s" % human_score_name(score))
        scoring_player_str = input("Which player scored a point (0/1)? ")
        if scoring_player_str not in ['0', '1']:
            print("Player must be 0 or 1")
            continue
        score = score_after_point(score, int(scoring_player_str))
    print(human_score_name(score))