如何在 python 中的 class 中可能實現輔助函數

Question

我對 python 相當陌生，我正在嘗試設計一個 class 來解決 N 皇后問題。 這是我的 class 定義：

class QueenSolver:

    def genEmptyBoard(self, n):
        # Generates an empty board of n width and n height
        board = []
        for _ in range(n):
            board.append([0 for _ in range(n)])
        return board

    def genLegalBoard(self, q1, q2, n):
        # Returns legal board or false
        board = self.genEmptyBoard(self, n)
        try:
            board[q1[0]][q1[1]] = 'q'
        except IndexError:
            print("Queen placed outside of board constraints")
            return False
        try:
            if board[q2[0]][q2[1]] == 'q':
                print("Queens cannot be placed in the same position")
                return False
            board[q2[0]][q2[1]] = 'Q'
        except IndexError:
            print("Queen placed outside of board constraints")
            return False 
        return board

但是，當我在 class 之外調用此方法時，如下所示：

board = QueenSolver.genLegalBoard([0, 0], [7, 7], 8)

我收到如下所示的錯誤：

Exception has occurred: TypeError
QueenSolver.genLegalBoard() missing 1 required positional argument: 'n'

顯然，當從 class 定義之外調用它時，我必須提供“self”變量？ 我認為“self”參數不需要任何值，因為它是假設的？ 我在這里想念什么？

Answer 1

在調用 class 的方法之前，您需要實例化一個 QueenSolver QueenSolver的 object。 以及，從board = self.genEmptyBoard(self, n)中刪除self 。

class QueenSolver:

    def genEmptyBoard(self, n):
        # Generates an empty board of n width and n height
        board = []
        for _ in range(n):
            board.append([0 for _ in range(n)])
        return board

    def genLegalBoard(self, q1, q2, n):
        # Returns legal board or false
        board = self.genEmptyBoard(n)
        try:
            board[q1[0]][q1[1]] = 'q'
        except IndexError:
            print("Queen placed outside of board constraints")
            return False
        try:
            if board[q2[0]][q2[1]] == 'q':
                print("Queens cannot be placed in the same position")
                return False
            board[q2[0]][q2[1]] = 'Q'
        except IndexError:
            print("Queen placed outside of board constraints")
            return False 
        return board

QS = QueenSolver()
board = QS.genLegalBoard([0, 0], [7, 7], 8)

Output：

 [['q', 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0, 'Q']]