Merge pull request #373 from tjd1234/35.evenwins.python

added evenwins.py

35_Even_Wins/python/evenwins.py

@@ -0,0 +1,206 @@
+# evenwins.py 
+
+#
+# This version of evenwins.bas based on game decscription and does *not*
+# follow the source. The computer chooses marbles at random.
+#
+# For simplicity, global variables are used to store the game state.
+# A good exercise would be to replace this with a class.
+#
+# The code is not short, but hopefully it is easy for beginners to understand
+# and modify.
+#
+# Infinite loops of the style "while True:" are used to simplify some of the
+# code. The "continue" keyword is used in a few places to jump back to the top
+# of the loop. The "return" keyword is also used to break out of functions.
+# This is generally considered poor style, but in this case it simplifies the
+# code and makes it easier to read (at least in my opinion). A good exercise
+# would be to remove these infinite loops, and uses of continue, to follow a
+# more structured style.
+#
+
+import random
+
+# global variables
+marbles_in_middle = -1
+human_marbles     = -1
+computer_marbles  = -1
+whose_turn        = ''
+
+# Only called during development for serious errors that are due to mistakes
+# in the program. Should never be called during a regular game.
+def serious_error(msg):
+    print('serious_error: ' + msg)
+    exit(1)
+
+def welcome_screen():
+    print('Welcome to Even Wins!')
+    print('Based on evenwins.bas from Creative Computing')
+    print()
+    print('Even Wins is a two-person game. You start with')
+    print('27 marbles in the middle of the table.')
+    print()
+    print('Players alternate taking marbles from the middle.')
+    print('A player can take 1 to 4 marbles on their turn, and')
+    print('turns cannot be skipped. The game ends when there are')
+    print('no marbles left, and the winner is the one with an even')
+    print('number of marbles.')
+    print()
+
+def marbles_str(n):
+    if n == 1: return '1 marble'
+    return f'{n} marbles'
+
+def choose_first_player():
+    global whose_turn
+    while True:
+        ans = input('Do you want to play first? (y/n) --> ')
+        if ans == 'y': 
+            whose_turn = 'human'
+            return
+        elif ans == 'n':
+            whose_turn = 'computer'
+            return
+        else:
+            print()
+            print('Please enter "y" if you want to play first,')
+            print('or "n" if you want to play second.')
+            print()
+
+def next_player():
+    global whose_turn
+    if whose_turn == 'human':
+        whose_turn = 'computer'
+    elif whose_turn == 'computer':
+        whose_turn = 'human'
+    else:
+        serious_error(f'play_game: unknown player {whose_turn}')
+
+# Converts a string s to an int, if possible.
+def to_int(s):
+    try:
+        n = int(s)
+        return True, n
+    except:
+        return False, 0
+
+def print_board():
+    global marbles_in_middle
+    global human_marbles
+    global computer_marbles
+    print()
+    print(f' marbles in the middle: {marbles_in_middle} ' + marbles_in_middle*'*')
+    print(f'    # marbles you have: {human_marbles}')
+    print(f'# marbles computer has: {computer_marbles}')
+    print()
+
+def human_turn():
+    global marbles_in_middle
+    global human_marbles
+
+    # get number in range 1 to min(4, marbles_in_middle)
+    max_choice = min(4, marbles_in_middle)
+    print("It's your turn!")
+    while True:
+        s = input(f'Marbles to take? (1 - {max_choice}) --> ')
+        ok, n = to_int(s)
+        if not ok:
+            print()
+            print(f'  Please enter a whole number from 1 to {max_choice}')
+            print()
+            continue
+        if n < 1:
+            print()
+            print('  You must take at least 1 marble!')
+            print()
+            continue
+        if n > max_choice:
+            print()
+            print(f'  You can take at most {marbles_str(max_choice)}')
+            print()
+            continue
+        print()
+        print(f'Okay, taking {marbles_str(n)} ...')
+        marbles_in_middle -= n
+        human_marbles += n
+        return
+
+def game_over():
+    global marbles_in_middle
+    global human_marbles
+    global computer_marbles
+    print()
+    print('!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!')
+    print('!! All the marbles are taken: Game Over!')
+    print('!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!')
+    print()
+    print_board()
+    if human_marbles % 2 == 0:
+        print('You are the winner! Congratulations!')
+    else:
+        print('The computer wins: all hail mighty silicon!')
+    print('')
+
+def computer_turn():
+    global marbles_in_middle
+    global computer_marbles
+
+    print("It's the computer's turn ...")
+    max_choice = min(4, marbles_in_middle)
+
+    # choose at random
+    n = random.randint(1, max_choice)
+    print(f'Computer takes {marbles_str(n)} ...')
+    marbles_in_middle -= n
+    computer_marbles += n
+
+def play_game():
+    global marbles_in_middle
+    global human_marbles
+    global computer_marbles
+
+    # initialize the game state
+    marbles_in_middle = 27
+    human_marbles = 0
+    computer_marbles = 0
+    print_board()
+
+    while True:
+        if marbles_in_middle == 0:
+            game_over()
+            return
+        elif whose_turn == 'human':
+            human_turn()
+            print_board()
+            next_player()
+        elif whose_turn == 'computer':
+            computer_turn()
+            print_board()
+            next_player()
+        else:
+            serious_error(f'play_game: unknown player {whose_turn}')
+
+def main():
+    global whose_turn
+
+    welcome_screen()
+
+    while True:
+        choose_first_player()
+        play_game()
+
+        # ask if the user if they want to play again
+        print()
+        again = input('Would you like to play again? (y/n) --> ')
+        if again == 'y':
+            print()
+            print("Ok, let's play again ...")
+            print()
+        else:
+            print()
+            print('Ok, thanks for playing ... goodbye!')
+            print()
+            return
+
+if __name__ == '__main__':
+    main()