使用Python编写数独游戏Sudoku教程

数独是各种应用程序中流行的益智类拼图游戏。数独板是一个9×9的网格，玩家必须在每行、每列和3×3的子网格中放置一次数字1到9，并且只能放置一次。游戏开始时，有几个空格已经用数字填充，称为givens。一个好的数独谜题应该只有一个可能的有效解决方案。

它的工作原理

数独网格类的对象是表示数独网格的数据结构。您可以调用它们的方法来修改网格或检索有关网格的信息。例如，makeMove（）方法在网格上放置一个数字，resetGrid（）方法将网格恢复到其原始状态，如果解决方案的所有数字都已放置在网格上，则isSolved（）返回True。

该程序的主要部分从第141行开始，为该游戏使用了一个数独网格对象及其方法，但您也可以将此类复制并粘贴到您创建的其他数独程序中，以重用其功能。

先直接上代码：

import copy, random, sysEMPTY_SPACE = '.'
GRID_LENGTH = 9
BOX_LENGTH = 3
FULL_GRID_SIZE = GRID_LENGTH * GRID_LENGTHclass SudokuGrid:def __init__(self, originalSetup):self.originalSetup = originalSetupself.grid = {}self.resetGrid()self.moves = []def resetGrid(self):"""Reset the state of the grid, tracked by self.grid, to thestate in self.originalSetup."""for x in range(1, GRID_LENGTH + 1):for y in range(1, GRID_LENGTH + 1):self.grid[(x, y)] = EMPTY_SPACEassert len(self.originalSetup) == FULL_GRID_SIZEi = 0y = 0while i < FULL_GRID_SIZE:for x in range(GRID_LENGTH):self.grid[(x, y)] = self.originalSetup[i]i += 1y += 1def makeMove(self, column, row, number):"""Place the number at the column (a letter from A to I) and row(an integer from 1 to 9) on the grid."""x = 'ABCDEFGHI'.find(column)y = int(row) - 1if self.originalSetup[y * GRID_LENGTH + x] != EMPTY_SPACE:return Falseself.grid[(x, y)] = numberself.moves.append(copy.copy(self.grid))return Truedef undo(self):"""Set the current grid state to the previous state in theself.moves list."""if self.moves == []:returnself.moves.pop()if self.moves == []:self.resetGrid()else:self.grid = copy.copy(self.moves[-1])def display(self):"""Display the current state of the grid on the screen."""print('   A B C   D E F   G H I')for y in range(GRID_LENGTH):for x in range(GRID_LENGTH):if x == 0:print(str(y + 1) + '  ', end='')print(self.grid[(x, y)] + ' ', end='')if x == 2 or x == 5:print('| ', end='')print()if y == 2 or y == 5:print('   ------+-------+------')def _isCompleteSetOfNumbers(self, numbers):"""Return True if numbers contains the digits 1 through 9."""return sorted(numbers) == list('123456789')def isSolved(self):"""Returns True if the current grid is in a solved state."""for row in range(GRID_LENGTH):rowNumbers = []for x in range(GRID_LENGTH):number = self.grid[(x, row)]rowNumbers.append(number)if not self._isCompleteSetOfNumbers(rowNumbers):return Falsefor column in range(GRID_LENGTH):columnNumbers = []for y in range(GRID_LENGTH):number = self.grid[(column, y)]columnNumbers.append(number)if not self._isCompleteSetOfNumbers(columnNumbers):return Falsefor boxx in (0, 3, 6):for boxy in (0, 3, 6):boxNumbers = []for x in range(BOX_LENGTH):for y in range(BOX_LENGTH):number = self.grid[(boxx + x, boxy + y)]boxNumbers.append(number)if not self._isCompleteSetOfNumbers(boxNumbers):return Falsereturn Trueprint('''Sudoku PuzzleSudoku is a number placement logic puzzle game. A Sudoku grid is a 9x9grid of numbers. Try to place numbers in the grid such that every row,column, and 3x3 box has the numbers 1 through 9 once and only once.For example, here is a starting Sudoku grid and its solved form:5 3 . | . 7 . | . . .     5 3 4 | 6 7 8 | 9 1 26 . . | 1 9 5 | . . .     6 7 2 | 1 9 5 | 3 4 8. 9 8 | . . . | . 6 .     1 9 8 | 3 4 2 | 5 6 7------+-------+------     ------+-------+------8 . . | . 6 . | . . 3     8 5 9 | 7 6 1 | 4 2 34 . . | 8 . 3 | . . 1 --> 4 2 6 | 8 5 3 | 7 9 17 . . | . 2 . | . . 6     7 1 3 | 9 2 4 | 8 5 6------+-------+------     ------+-------+------. 6 . | . . . | 2 8 .     9 6 1 | 5 3 7 | 2 8 4. . . | 4 1 9 | . . 5     2 8 7 | 4 1 9 | 6 3 5. . . | . 8 . | . 7 9     3 4 5 | 2 8 6 | 1 7 9''')input('Press Enter to begin...')with open('data.txt') as puzzleFile:puzzles = puzzleFile.readlines()for i, puzzle in enumerate(puzzles):puzzles[i] = puzzle.strip()grid = SudokuGrid(random.choice(puzzles))while True:grid.display()if grid.isSolved():print('Congratulations! You solved the puzzle!')print('Thanks for playing!')sys.exit()while True:print()print('Enter a move, or RESET, NEW, UNDO, ORIGINAL, or QUIT:')print('(For example, a move looks like "B4 9".)')action = input('> ').upper().strip()if len(action) > 0 and action[0] in ('R', 'N', 'U', 'O', 'Q'):breakif len(action.split()) == 2:space, number = action.split()if len(space) != 2:continuecolumn, row = spaceif column not in list('ABCDEFGHI'):print('There is no column', column)continueif not row.isdecimal() or not (1 <= int(row) <= 9):print('There is no row', row)continueif not (1 <= int(number) <= 9):print('Select a number from 1 to 9, not ', number)continuebreakprint()if action.startswith('R'):grid.resetGrid()continueif action.startswith('N'):grid = SudokuGrid(random.choice(puzzles))continueif action.startswith('U'):grid.undo()continueif action.startswith('O'):originalGrid = SudokuGrid(grid.originalSetup)print('The original grid looked like this:')originalGrid.display()input('Press Enter to continue...')if action.startswith('Q'):print('Thanks for playing!')sys.exit()if grid.makeMove(column, row, number) == False:print('You cannot overwrite the original grid\'s numbers.')print('Enter ORIGINAL to view the original grid.')input('Press Enter to continue...')

运行sudoku.py时，输出将如下所示：