数独是报纸和手机应用中流行的益智游戏。数独棋盘是一个9 × 9的格子，玩家必须将数字 1 到 9 放置一次，并且只能放置一次，在每行、每列和3 × 3的子格子中。游戏开始时，一些空格已经用数字填满，称为预设。一个格式良好的数独谜题将只有一个可能的有效解。
当您运行sudoku.py时，输出如下：
Sudoku Puzzle, by Al Sweigart email@protected
`--snip--`
A B C D E F G H I
1 . . . | . . . | . . .
2 . 7 9 | . 5 . | 1 8 .
3 8 . . | . . . | . . 7
------+-------+------
4 . . 7 | 3 . 6 | 8 . .
5 4 5 . | 7 . 8 | . 9 6
6 . . 3 | 5 . 2 | 7 . .
------+-------+------
7 7 . . | . . . | . . 5
8 . 1 6 | . 3 . | 4 2 .
9 . . . | . . . | . . .
Enter a move, or RESET, NEW, UNDO, ORIGINAL, or QUIT:
(For example, a move looks like "B4 9".)
`--snip--`SudokuGrid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，或者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()方法将网格恢复到原始状态，如果所有解决方案的数字都已放置在网格上，isSolved()将返回True。
从第 141 行开始，程序的主要部分为这个游戏使用了一个SudokuGrid对象及其方法，但是您也可以将这个类复制并粘贴到您创建的其他数独程序中，以重用它的功能。
"""Sudoku Puzzle, by Al Sweigart email@protected
The classic 9x9 number placement puzzle.
More info at https://en.wikipedia.org/wiki/Sudoku
This code is available at https://nostarch.com/big-book-small-python-programming
Tags: large, game, object-oriented, puzzle"""
import copy, random, sys
# This game requires a sudokupuzzle.txt file that contains the puzzles.
# Download it from https://inventwithpython.com/sudokupuzzles.txt
# Here's a sample of the content in this file:
# ..3.2.6..9..3.5..1..18.64....81.29..7.......8..67.82....26.95..8..2.3..9..5.1.3..
# 2...8.3...6..7..84.3.5..2.9...1.54.8.........4.27.6...3.1..7.4.72..4..6...4.1...3
# ......9.7...42.18....7.5.261..9.4....5.....4....5.7..992.1.8....34.59...5.7......
# .3..5..4...8.1.5..46.....12.7.5.2.8....6.3....4.1.9.3.25.....98..1.2.6...8..6..2.
# Set up the constants:
EMPTY_SPACE = '.'
GRID_LENGTH = 9
BOX_LENGTH = 3
FULL_GRID_SIZE = GRID_LENGTH * GRID_LENGTH
class SudokuGrid:
def __init__(self, originalSetup):
# originalSetup is a string of 81 characters for the puzzle
# setup, with numbers and periods (for the blank spaces).
# See https://inventwithpython.com/sudokupuzzles.txt
self.originalSetup = originalSetup
# The state of the sudoku grid is represented by a dictionary
# with (x, y) keys and values of the number (as a string) at
# that space.
self.grid = {}
self.resetGrid() # Set the grid state to its original setup.
self.moves = [] # Tracks each move for the undo feature.
def resetGrid(self):
"""Reset the state of the grid, tracked by self.grid, to the
state in self.originalSetup."""
for x in range(1, GRID_LENGTH + 1):
for y in range(1, GRID_LENGTH + 1):
self.grid[(x, y)] = EMPTY_SPACE
assert len(self.originalSetup) == FULL_GRID_SIZE
i = 0 # i goes from 0 to 80
y = 0 # y goes from 0 to 8
while i < FULL_GRID_SIZE:
for x in range(GRID_LENGTH):
self.grid[(x, y)] = self.originalSetup[i]
i += 1
y += 1
def 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) # Convert this to an integer.
y = int(row) - 1
# Check if the move is being made on a "given" number:
if self.originalSetup[y * GRID_LENGTH + x] != EMPTY_SPACE:
return False
self.grid[(x, y)] = number # Place this number on the grid.
# We need to store a separate copy of the dictionary object:
self.moves.append(copy.copy(self.grid))
return True
def undo(self):
"""Set the current grid state to the previous state in the
self.moves list."""
if self.moves == []:
return # No states in self.moves, so do nothing.
self.moves.pop() # Remove the current state.
if self.moves == []:
self.resetGrid()
else:
# set the grid to the last move.
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') # Display column labels.
for y in range(GRID_LENGTH):
for x in range(GRID_LENGTH):
if x == 0:
# Display row label:
print(str(y + 1) + ' ', end='')
print(self.grid[(x, y)] + ' ', end='')
if x == 2 or x == 5:
# Display a vertical line:
print('| ', end='')
print() # Print a newline.
if y == 2 or y == 5:
# Display a horizontal line:
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."""
# Check each row:
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 False
# Check each column:
for 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 False
# Check each box:
for 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 False
return True
print('''Sudoku Puzzle, by Al Sweigart email@protected
Sudoku is a number placement logic puzzle game. A Sudoku grid is a 9x9
grid 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 2
6 . . | 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 3
4 . . | 8 . 3 | . . 1 --> 4 2 6 | 8 5 3 | 7 9 1
7 . . | . 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...')
# Load the sudokupuzzles.txt file:
with open('sudokupuzzles.txt') as puzzleFile:
puzzles = puzzleFile.readlines()
# Remove the newlines at the end of each puzzle:
for i, puzzle in enumerate(puzzles):
puzzles[i] = puzzle.strip()
grid = SudokuGrid(random.choice(puzzles))
while True: # Main game loop.
grid.display()
# Check if the puzzle is solved.
if grid.isSolved():
print('Congratulations! You solved the puzzle!')
print('Thanks for playing!')
sys.exit()
# Get the player's action:
while True: # Keep asking until the player enters a valid action.
print() # Print a newline.
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'):
# Player entered a valid action.
break
if len(action.split()) == 2:
space, number = action.split()
if len(space) != 2:
continue
column, row = space
if column not in list('ABCDEFGHI'):
print('There is no column', column)
continue
if not row.isdecimal() or not (1 <= int(row) <= 9):
print('There is no row', row)
continue
if not (1 <= int(number) <= 9):
print('Select a number from 1 to 9, not ', number)
continue
break # Player entered a valid move.
print() # Print a newline.
if action.startswith('R'):
# Reset the grid:
grid.resetGrid()
continue
if action.startswith('N'):
# Get a new puzzle:
grid = SudokuGrid(random.choice(puzzles))
continue
if action.startswith('U'):
# Undo the last move:
grid.undo()
continue
if action.startswith('O'):
# View the original numbers:
originalGrid = SudokuGrid(grid.originalSetup)
print('The original grid looked like this:')
originalGrid.display()
input('Press Enter to continue...')
if action.startswith('Q'):
# Quit the game.
print('Thanks for playing!')
sys.exit()
# Handle the move the player selected.
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...') 试着找出下列问题的答案。尝试对代码进行一些修改，然后重新运行程序，看看这些修改有什么影响。
- 删除或重命名
sudokuzicks.txt文件并运行程序会出现什么错误？ - 如果把第 91 行的
str(y + 1)改成str(y)会怎么样？ - 如果把第 99 行的
if y == 2 or y == 5:改成if y == 1 or y == 6:会怎么样？