fixed issue 7

arcade/games/tictactoe.py

@@ -1,6 +1,6 @@
 """Tic Tac Toe.
 
-You are X, the computer is O. Squares are numbered 1-9 like a phone keypad:
+You are X, the computer is O. Squares are numbered 1-9:
 
     1 | 2 | 3
     --+---+--
@@ -26,12 +26,12 @@
 WINNING_LINES = [
     (0, 1, 2),
     (3, 4, 5),
-    (6, 7, 8),  # rows
+    (6, 7, 8),
     (0, 3, 6),
     (1, 4, 7),
-    (2, 5, 8),  # columns
+    (2, 5, 8),
     (0, 4, 8),
-    (2, 4, 6),  # diagonals
+    (2, 4, 6),
 ]
 
 
@@ -43,15 +43,13 @@ def new_board() -> list[str]:
 def render(board: list[str]) -> str:
     """Draw the board as text.
 
-    Empty squares show their number, so the player can see what to type.
-
-    Args:
-        board: Nine squares, each "X", "O", or a space.
-
-    Returns:
-        A multi-line string ready to print.
+    Empty squares show their number so the player knows what to enter.
     """
-    cells = [board[i] if board[i] != EMPTY else str(i + 1) for i in range(9)]
+    cells = [
+        board[i] if board[i] != EMPTY else str(i + 1)
+        for i in range(9)
+    ]
+
     return (
         f"\n     {cells[0]} | {cells[1]} | {cells[2]}\n"
         f"    ---+---+---\n"
@@ -62,50 +60,41 @@ def render(board: list[str]) -> str:
 
 
 def winner(board: list[str]) -> str | None:
-    """Return the mark that has won, or None if nobody has yet.
-
-    Args:
-        board: The current board.
-
-    Returns:
-        "X", "O", or None.
-    """
+    """Return the winning mark, or None if there is no winner."""
     for a, b, c in WINNING_LINES:
-        if board[a] != EMPTY and board[a] == board[b] == board[c]:
+        if (
+            board[a] != EMPTY
+            and board[a] == board[b]
+            and board[b] == board[c]
+        ):
             return board[a]
+
     return None
 
 
 def free_squares(board: list[str]) -> list[int]:
-    """Return the indexes of every square that is still empty."""
-    return [i for i, cell in enumerate(board) if cell == EMPTY]
+    """Return the indexes of all empty squares."""
+    return [
+        i for i, cell in enumerate(board)
+        if cell == EMPTY
+    ]
 
 
 def is_full(board: list[str]) -> bool:
-    """Return True if there are no empty squares left."""
+    """Return True if the board has no empty squares."""
     return EMPTY not in board
 
 
 def computer_move(board: list[str]) -> int:
-    """Choose a square for the computer.
-
-    Currently picks at random from the free squares. There is an open issue to
-    make this cleverer if you fancy it.
-
-    Args:
-        board: The current board.
-
-    Returns:
-        The index of the square to play.
-    """
+    """Choose a random empty square for the computer."""
     return random.choice(free_squares(board))
 
 
 def play() -> int:
     """Run one game of Tic Tac Toe.
 
     Returns:
-        100 points for a win, 0 otherwise.
+        100 points if the player wins, otherwise 0.
     """
     print(art.banner("TIC TAC TOE"))
     print(f"\n  You are {PLAYER}. The computer is {COMPUTER}.")
@@ -114,27 +103,70 @@ def play() -> int:
     result = None
 
     while result is None and not is_full(board):
+
+        # Display current board
         print(render(board))
 
+        # -----------------------------
+        # Player's move
+        # -----------------------------
         while True:
-            choice = ask_int("  Your move (1-9):", minimum=1, maximum=9)
-            if board[choice - 1] == EMPTY:
-                board[choice - 1] = PLAYER
+            choice = ask_int(
+                "  Your move (1-9): ",
+                minimum=1,
+                maximum=9
+            )
+
+            index = choice - 1
+
+            if board[index] == EMPTY:
+                board[index] = PLAYER
                 break
-            print(art.red("  That square is taken. Pick another."))
 
+            print(
+                art.red(
+                    "  That square is taken. Pick another."
+                )
+            )
+
+        # Check if player won
         result = winner(board)
-        if result is not None or is_full(board):
+
+        if result is not None:
             break
 
+        # Check for draw
+        if is_full(board):
+            break
+
+        # -----------------------------
+        # Computer's move
+        # -----------------------------
         move = computer_move(board)
         board[move] = COMPUTER
-        print(art.dim(f"\n  Computer plays square {move + 1}."))
+
+        print(
+            art.dim(
+                f"\n  Computer plays square {move + 1}."
+            )
+        )
+
+        # Check if computer won
         result = winner(board)
 
+    # -----------------------------
+    # Game over
+    # -----------------------------
     print(render(board))
-    print(f"  {result} wins!\n")
 
     if result == PLAYER:
+        print("  You win!\n")
         return 100
-    return 0
+
+    elif result == COMPUTER:
+        print("  Computer wins!\n")
+        return 0
+
+    else:
+        print("  It's a draw!\n")
+        return 0