A game of 501.

★★☆

Darts is a game for two players. The objective of the game is to reach a score of exactly zero, starting from 501. In each turn a player throws up to three darts. Each dart can score 0-20, a double 1-20, a triple 1-20, a 25 or 50.

Make

Write a program to simulate the scoring for the game of darts.

If the total of the darts thrown in a turn when subtracted from the player’s remaining score equals one, or less than zero then the player scores zero and their turn is over.

If the total of one or more darts thrown in a turn would result in a score of exactly zero when subtracted from the remaining score, and the last dart thrown is a double, the player wins. 50 counts as double 25.

In all other cases the total of the three darts thrown is subtracted from the score remaining and the other player then takes their turn.

Success Criteria

Remember to add a comment before a subprogram, selection or iteration statement to explain its purpose.

Complete the subprogram called is_dart_valid that:

1. Returns True if the score of a single dart is valid, or False if it is not. A valid dart is…
2. …any score between zero and twenty.
3. …twenty five or fifty.
4. …a double. A double can be any dart scoring forty or less that is an even number.
5. …a triple. A triple can be any dart scoring sixty or less that is divisible by three.

Complete the subprogram called play_game that:

1. Outputs whose turn it is and their current score.
2. Allows the user to input up to three darts in a turn, validating each dart.
3. Checks if the dart thrown causes the player to win.
4. Updates the player score by deducting the total of the three darts from their score if that results in a score of more than one.
5. Plays the game until a player wins.
6. Outputs the winner.

Complete the main program so that:

1. The scores of the two players are stored in a list called score and both start at 501 (for testing start at 101).
2. Calls the play_game procedure.

Typical inputs and outputs from the program would be:

Player 1 it's your turn. Your score is: 501
Dart 1
Enter score: 60
Treble 20
Dart 2
Enter score: 60
Treble 20
Dart 3
Enter score: 20
140 scored.

Player 2 it's your turn. Your score is: 501
Dart 1
Enter score: 20
Dart 2
Enter score: 57
Treble 19
Dart 3
Enter score: 19
96 scored.

Player 1 it's your turn. Your score is: 361
Dart 1
Enter score: 60
Treble 20
Dart 2
Enter score: 15
Dart 3
Enter score: 20
95 scored.

Player 2 it's your turn. Your score is: 405
Dart 1
Enter score: 60
Treble 20
Dart 2
Enter score: 20
Dart 3
Enter score: 1
81 scored.

Player 1 it's your turn. Your score is: 266
Dart 1
Enter score: 60
Treble 20
Dart 2
Enter score: 57
Treble 19
Dart 3
Enter score: 57
Treble 19
174 scored.

Player 2 it's your turn. Your score is: 324
Dart 1
Enter score: 20
Dart 2
Enter score: 20
Dart 3
Enter score: 20
60 scored.

Player 1 it's your turn. Your score is: 92
Dart 1
Enter score: 60
Treble 20
Dart 2
Enter score: 32
Double 16
92 scored.
Player 1 wins the leg.

# Check if a score for one dart is valid
def is_dart_valid(dart):
---
    valid = False
---
    # Single or low double/treble thrown
---
    if dart > -1 and dart < 21:
---
        valid = True
---
    # Bullseye or 25 thrown
---
    elif dart == 25 or dart == 50:
---
        valid = True
        print("Shot!")
---
    # Double thrown
---
    elif dart % 2 == 0 and dart <= 40:
---
        valid = True
---
        print("Double", int(dart / 2))
---
    # Treble thrown
---
    elif dart % 3 == 0 and dart <= 60:
---
        valid = True
---
        print("Treble", int(dart / 3))
---
    return valid

# Play the game
def play_game():
---
    player = 0
    winner = -1
---
    # Play until one player reaches zero with a double
    while winner == -1:
---
        print("Player", player + 1, "it's your turn. Your score is:", score[player])
        darts_thrown = 0
        total = 0
        valid_dart = False
---
        # Throw up to 3 darts unless the leg is won sooner
        while valid_dart == False or darts_thrown < 3 and winner == -1:
---
            print("Dart", darts_thrown + 1)
            dart = int(input("Enter score: "))
---
            # Keep a running total of the darts for the turn
            valid_dart = is_dart_valid(dart)
---
            # If the dart is valid, process the score
            if valid_dart:
---
                darts_thrown = darts_thrown + 1
                total = total + dart
---
                # Player wins if they reach exactly zero and threw a double with the dart
                if score[player] - total == 0 and dart % 2 == 0:
---
                    winner = player + 1
---
                # Bust score
                elif score[player] - total < 0 or score[player] - total == 1:
---
                    print("Bust!")
                    darts_thrown = 3
                    total = 0
---
            else:
---
                print("Invalid dart.")
---
        print(total, "scored.")
        score[player] = score[player] - total
---
        # Next player
        print()
---
        player = (player + 1) % 2
---
    print("Player", winner, "wins the leg.")
---
        

# -------------------------
# Main program
# -------------------------
score = [101, 101]
play_game()