crosswordpuzzle.py

   1 # Get A Clue (C) 2010 V. Harishankar
   2 # Crossword puzzle maker program
   3 # Licensed under the GNU GPL v3
   4
   5 # Class for the puzzle data representation
   6
   7 # for export to PNG image
   8 import cairo
   9
  10 class GridItem:
  11         # initialize the item
  12         def __init__ (self, item_char='.', item_guess = None, across_start = False,
  13                                         down_start = False,     occupied_across = False,
  14                                         occupied_down = False, num = 0, clue_across = None,
  15                                         clue_down = None, revealed = False):
  16                 # character in the cell
  17                 self.char = item_char
  18                 # guess of character in cell
  19                 self.guess = item_guess
  20                 # is the cell the start of an across word?
  21                 self.across_start = across_start
  22                 # is the cell the start of a down word?
  23                 self.down_start = down_start
  24                 # is the cell occupied by a letter in an across word?
  25                 self.occupied_across = occupied_across
  26                 # is the cell occupied by a letter in a down word?
  27                 self.occupied_down = occupied_down
  28                 # numbering of the cell if it is the start of a word
  29                 self.numbered = num
  30                 # clue across if the cell is the start of an across word
  31                 self.clue_across = clue_across
  32                 # clue down if the cell is the start of a down word
  33                 self.clue_down = clue_down
  34                 # is the letter revealed or hidden?
  35                 self.revealed = revealed
  36
  37         # clear the across data
  38         def clear_across_data (self):
  39                 self.across_start = False
  40                 self.occupied_across = False
  41                 self.clue_across = None
  42                 # if no down word starting at item
  43                 if self.down_start is False:
  44                         self.numbered = 0
  45                 # if no down word at the item
  46                 if self.occupied_down is False:
  47                         self.char = '.'
  48                         self.revealed = False
  49                         self.guess = None
  50
  51         # clear the down data
  52         def clear_down_data (self):
  53                 self.down_start = False
  54                 self.occupied_down = False
  55                 self.clue_down = None
  56                 # if no across word starting at item
  57                 if self.across_start is False:
  58                         self.numbered = 0
  59                 # if no across word at the item
  60                 if self.occupied_across is False:
  61                         self.char = '.'
  62                         self.revealed = False
  63                         self.guess = None
  64
  65         # reset a grid item completely - use only to destroy whole grid, otherwise
  66         # use either clear_across_data () or clear_down_data () for erasing single
  67         # words
  68         def reset (self):
  69                 # character in the cell
  70                 self.char = '.'
  71                 # guess of character in cell
  72                 self.guess = None
  73                 # is the cell the start of an across word?
  74                 self.across_start = False
  75                 # is the cell the start of a down word?
  76                 self.down_start = False
  77                 # is the cell occupied by a letter in an across word?
  78                 self.occupied_across = False
  79                 # is the cell occupied by a letter in a down word?
  80                 self.occupied_down = False
  81                 # numbering of the cell if it is the start of a word
  82                 self.numbered = 0
  83                 # clue across if the cell is the start of an across word
  84                 self.clue_across = None
  85                 # clue down if the cell is the start of a down word
  86                 self.clue_down = None
  87                 # is the letter revealed or hidden?
  88                 self.revealed = False
  89
  90 # exception for too long words
  91 class TooLongWordException (Exception):
  92         def __init__ (self, word, length):
  93                 self.word = word
  94                 self.length = length
  95
  96 # exception for intersecting words
  97 class IntersectWordException (Exception):
  98         def __init__ (self, word, length):
  99                 self.word = word
 100                 self.length = length
 101
 102 # exception when grid is sought to be changed when frozen
 103 class FrozenGridException (Exception):
 104         def __init__ (self):
 105                 self.msg = "Grid is frozen and cannot be edited"
 106
 107 # exception when no word is found at a position
 108 class NoWordException (Exception):
 109         def __init__ (self, row, col):
 110                 self.pos = (row, col)
 111
 112 # exception when a word number is not found in the grid
 113 class NoNumberException (Exception):
 114         def __init__ (self, num):
 115                 self.num = num
 116
 117 # exception when no words are present in the grid
 118 class NoWordsException (Exception):
 119         def __init__ (self):
 120                 self.msg = "No words in grid"
 121
 122 # exception to raise when solution is imcomplete when trying to verify it
 123 class IncompleteSolutionException (Exception):
 124         def __init__ (self):
 125                 self.msg = "Solution incomplete"
 126
 127 class CrosswordPuzzle:
 128         def __init__ (self, rows, cols):
 129                 # define number of rows and columns
 130                 self.rows = rows
 131                 self.cols = cols
 132
 133                 # initialize the list to hold the grid
 134                 self.data = []
 135
 136                 # initial state of the grid is unfrozen
 137                 self.frozen_grid = False
 138
 139                 # create the grid data
 140                 for i in range (rows):
 141                         self.data.append ([])
 142                         for j in range (cols):
 143                                 self.data[i].append (GridItem ())
 144
 145         # export to an image
 146         def export_image (self, pngfile, htmlfile=None, puztitle="Crossword Puzzle",
 147                 solution=True):
 148                 # don't export if grid is not frozen
 149                 self.assert_frozen_grid ()
 150
 151                 # create cairo image surface and context
 152                 px = 30
 153                 surf = cairo.ImageSurface (cairo.FORMAT_RGB24, self.cols*px, self.rows*px)
 154                 ctx = cairo.Context (surf)
 155
 156                 ctx.set_source_rgb (1, 1, 1)
 157                 ctx.rectangle (0, 0, self.cols*px, self.rows*px)
 158                 ctx.fill ()
 159
 160                 # get the clues across and down
 161                 clues_across = self.get_clues_across ()
 162                 clues_down = self.get_clues_down ()
 163
 164
 165                 # traverse through the grid
 166                 for row in range (self.rows):
 167                         for col in range (self.cols):
 168                                 # if grid is un-occupied
 169                                 if (self.data[row][col].occupied_across is False and
 170                                         self.data[row][col].occupied_down is False):
 171                                         ctx.set_source_rgb (0, 0, 0)
 172                                         ctx.rectangle (col*px, row*px, px, px)
 173                                         ctx.fill ()
 174                                 # grid is occupied
 175                                 else:
 176                                         ctx.set_source_rgb (1, 1, 1)
 177                                         ctx.rectangle (col*px, row*px, px, px)
 178                                         ctx.fill ()
 179                                         ctx.set_source_rgb (0, 0, 0)
 180                                         ctx.rectangle (col*px, row*px, px, px)
 181                                         ctx.stroke ()
 182                                         # if solution is not to be provided, number the grid
 183                                         if solution is False:
 184                                                 if self.data[row][col].numbered <> 0:
 185                                                         ctx.select_font_face ("Serif")
 186                                                         ctx.set_font_size (10)
 187                                                         ctx.move_to (col*px+5, row*px+10)
 188                                                         ctx.show_text (str(self.data[row][col].numbered))
 189                                         # display the words
 190                                         else:
 191                                                 ctx.select_font_face ("Serif")
 192                                                 ctx.set_font_size (16)
 193                                                 ctx.move_to (col*px+10, row*px+20)
 194                                                 ctx.show_text (self.data[row][col].char)
 195
 196                 surf.write_to_png (open (pngfile, "wb"))
 197
 198                 # if solution is false, publish the clues and the image in a HTML file
 199                 if htmlfile and solution is False:
 200                         html_contents = ["<html>", "<head>", "<title>"]
 201                         html_contents.append (puztitle)
 202                         html_contents.append ("</title>")
 203                         html_contents.append ("</head>")
 204                         html_contents.append ("<body>")
 205                         html_contents.append ("<h1>" + puztitle + "</h1>")
 206                         html_contents.append ('<img src="' + pngfile + '" alt="puzzle" />')
 207
 208                         html_contents.append ("<h2>Across clues</h2>")
 209                         html_contents.append ("<p>")
 210                         for word, clue in clues_across:
 211                                 # clue should be: <num> - clue text (chars)
 212                                 clue_str = str (self.data[word[1]][word[2]].numbered) + " - " \
 213                                                         + clue + " (" + str (word[3]) + ")"
 214                                 html_contents.append (clue_str)
 215                                 html_contents.append ("<br />")
 216                         html_contents.append ("</p>")
 217
 218                         html_contents.append ("<h2>Down clues</h2>")
 219                         html_contents.append ("<p>")
 220                         for word, clue in clues_down:
 221                                 clue_str = str (self.data[word[1]][word[2]].numbered) + " - " \
 222                                                         + clue + " (" + str (word[3]) + ")"
 223                                 html_contents.append (clue_str)
 224                                 html_contents.append ("<br />")
 225                         html_contents.append ("</p>")
 226                         html_contents.append ("</body>")
 227                         html_contents.append ("</html>")
 228
 229                         html_str = "\r\n".join (html_contents)
 230
 231                         fhtml = open (htmlfile, "wb")
 232                         fhtml.write (html_str)
 233                         fhtml.close ()
 234
 235         # get the AcrossLite(TM) data for exporting
 236         def export_acrosslite (self, title, author, copyright):
 237                 # don't export if grid is not frozen
 238                 self.assert_frozen_grid ()
 239
 240                 across_data = []
 241                 across_data.append ("<ACROSS PUZZLE>\r\n")
 242                 across_data.append ("<TITLE>\r\n")
 243                 across_data.append (title + "\r\n")
 244                 across_data.append ("<AUTHOR>\r\n")
 245                 across_data.append (author + "\r\n")
 246                 across_data.append ("<COPYRIGHT>\r\n")
 247                 across_data.append (copyright + "\r\n")
 248                 across_data.append ("<SIZE>\r\n")
 249                 str_size = str (self.cols) + "x" + str (self.rows)
 250                 across_data.append (str_size + "\r\n")
 251                 across_data.append ("<GRID>\r\n")
 252                 for row in range (self.rows):
 253                         for col in range (self.cols):
 254                                 if (self.data[row][col].occupied_across is True or
 255                                         self.data[row][col].occupied_down is True):
 256                                         across_data.append (self.data[row][col].char)
 257                                 else:
 258                                         across_data.append (".")
 259                         across_data.append ("\r\n")
 260
 261                 across_data.append ("<ACROSS>\r\n")
 262                 clues_across = self.get_clues_across ()
 263                 for word, clue in clues_across:
 264                         if clue:
 265                                 across_data.append (clue + "\r\n")
 266                         else:
 267                                 across_data.append ("(No clue yet)\r\n")
 268
 269                 across_data.append ("<DOWN>\r\n")
 270                 clues_down = self.get_clues_down ()
 271                 for word, clue in clues_down:
 272                         if clue:
 273                                 across_data.append (clue + "\r\n")
 274                         else:
 275                                 across_data.append ("(No clue yet\r\n")
 276
 277                 acrosslite_str = "".join (across_data)
 278                 return acrosslite_str
 279
 280         # get all the clues for across
 281         def get_clues_across (self):
 282                 clues = []
 283                 # traverse the grid
 284                 for row in range (self.rows):
 285                         for col in range (self.cols):
 286                                 if (self.data[row][col].occupied_across is True and
 287                                 self.data[row][col].across_start is True):
 288                                         word_across = self.get_word_across (row, col)
 289                                         clues.append ((word_across, self.data[row][col].clue_across))
 290                 # if no across words are found at all
 291                 if not clues:
 292                         raise NoWordsException
 293
 294                 return clues
 295
 296         # get all the clues for down
 297         def get_clues_down (self):
 298                 clues = []
 299                 # traverse the grid
 300                 for row in range (self.rows):
 301                         for col in range (self.cols):
 302                                 if (self.data[row][col].occupied_down is True and
 303                                 self.data[row][col].down_start is True):
 304                                         word_down = self.get_word_down (row, col)
 305                                         clues.append ((word_down, self.data[row][col].clue_down))
 306                 # if no down words are found at all
 307                 if not clues:
 308                         raise NoWordsException
 309
 310                 return clues
 311
 312         # getting an across word at a number (note that the grid should be
 313         # frozen for calling this otherwise a FrozenGridException will be raised)
 314         def get_word_across_at_num (self, num):
 315                 # assert that the grid is frozen
 316                 self.assert_frozen_grid ()
 317
 318                 # traverse the grid
 319                 for row in range (self.rows):
 320                         for col in range (self.cols):
 321                                 if self.data[row][col].numbered == num:
 322                                         word = self.get_word_across (row, col)
 323                                         return word
 324
 325                 # if number is not found
 326                 raise NoNumberException (num)
 327
 328         # getting a down word at a number (note that the grid should be frozen
 329         # for calling this otherwise a FrozenGridException will be raised)
 330         def get_word_down_at_num (self, num):
 331                 # assert that the grid is frozen
 332                 self.assert_frozen_grid ()
 333
 334                 # traverse the grid
 335                 for row in range (self.rows):
 336                         for col in range (self.cols):
 337                                 if self.data[row][col].numbered == num:
 338                                         word = self.get_word_down (row, col)
 339                                         return word
 340
 341                 # if number is not found
 342                 raise NoNumberException (num)
 343
 344         # getting the position of a number on the grid (note that the grid should
 345         # be frozen for calling this otherwise a FrozenGridException will be raised)
 346         def get_position_of_num (self, num):
 347                 # assert that the grid is frozen
 348                 self.assert_frozen_grid ()
 349
 350                 # traverse the grid
 351                 for row in range (self.rows):
 352                         for col in range (self.cols):
 353                                 if self.data[row][col].numbered == num:
 354                                         return (row, col)
 355
 356                 # if number is not found
 357                 raise NoNumberException (num)
 358
 359         # getting a down word at a position
 360         def get_word_down (self, row, col):
 361                 # if index is out of bounds
 362                 if row >= self.rows or col >= self.cols:
 363                         raise NoWordException (row, col)
 364
 365                 # if there is no occupied down letter at that position
 366                 if self.data[row][col].occupied_down is False:
 367                         raise NoWordException (row, col)
 368
 369                 # now traverse the grid to find the beginning of the word
 370                 i = row
 371                 while i >= 0:
 372                         # if it is occupied down and is the beginning of the word
 373                         if (self.data[i][col].occupied_down is True and
 374                                 self.data[i][col].down_start is True):
 375                                 start_row = i
 376                                 break
 377                         i -= 1
 378
 379                 i = start_row
 380                 word_chars = []
 381                 # now seek the end of the word
 382                 while i < self.rows:
 383                         if self.data[i][col].occupied_down is True:
 384                                 word_chars.append (self.data[i][col].char)
 385                         else:
 386                                 break
 387                         i += 1
 388
 389                 word = "".join (word_chars)
 390
 391                 # return the word, starting row, column and length as a tuple
 392                 return (word, start_row, col, len(word))
 393
 394         # getting an across word at a position
 395         def get_word_across (self, row, col):
 396                 # if index is out of bounds
 397                 if row >= self.rows or col >= self.cols:
 398                         raise NoWordException (row, col)
 399
 400                 # if there is no occupied across letter at that position
 401                 if self.data[row][col].occupied_across is False:
 402                         raise NoWordException (row, col)
 403
 404                 # now traverse the grid to look for the beginning of the word
 405                 i = col
 406                 while i >= 0:
 407                         # if it is occupied across and is the beginning of the word
 408                         if (self.data[row][i].occupied_across is True and
 409                                 self.data[row][i].across_start is True):
 410                                 start_col = i
 411                                 break
 412                         i -= 1
 413
 414                 i = start_col
 415                 word_chars = []
 416                 # now seek the end of the word
 417                 while i < self.cols:
 418                         if self.data[row][i].occupied_across is True:
 419                                 word_chars.append (self.data[row][i].char)
 420                         else:
 421                                 break
 422                         i += 1
 423
 424                 word = "".join (word_chars)
 425
 426                 # return the word, starting column, row and length as a tuple
 427                 return (word, row, start_col, len(word))
 428
 429         # setting a down word
 430         def set_word_down (self, row, col, word):
 431                 # if the grid is frozen then abort
 432                 self.assert_unfrozen_grid ()
 433
 434                 # if the word length greater than totalrows - startrow
 435                 if len(word) > self.rows - row:
 436                         raise TooLongWordException (word, len(word))
 437
 438                 # is the word intersecting any other word?
 439                 for i in range (len(word)):
 440                         # on the same column
 441                         if self.data[row+i][col].occupied_down is True:
 442                                 raise IntersectWordException (word, len(word))
 443                         # on the previous column except first column
 444                         if col > 0:
 445                                 # except the first and last col
 446                                 if i > 0 and i < len(word) - 1:
 447                                         if self.data[row+i][col-1].occupied_down is True:
 448                                                 raise IntersectWordException (word, len(word))
 449                                 # if the previous column is the end of an across word
 450                                 if (self.data[row+i][col-1].occupied_across is True and
 451                                         self.data[row+i][col].occupied_across is False):
 452                                         raise IntersectWordException (word, len(word))
 453
 454                         # on the next column except last column
 455                         if col < len(word) - 1:
 456                                 # except the first and last row check if there is any
 457                                 # down word in previous column
 458                                 if i > 0 and i < len(word) - 1:
 459                                         if self.data[row+i][col+1].occupied_down is True:
 460                                                 raise IntersectWordException (word, len(word))
 461                                 # check if there is any across word starting in the
 462                                 # next column
 463                                 if self.data[row+i][col+1].across_start is True:
 464                                         raise IntersectWordException (word, len(word))
 465
 466                 # also check the character before and after
 467                 if (row > 0 and self.data[row-1][col].occupied_down is True
 468                         and self.data[row-1][col].occupied_across is True):
 469                         raise IntersectWordException (word, len(word))
 470                 if (row + len(word) < self.rows and
 471                         self.data[row+len(word)][col].occupied_across is True and
 472                         self.data[row+len(word)][col].occupied_down is True):
 473                         raise IntersectWordException (word, len(word))
 474
 475                 # set the down start to true
 476                 self.data[row][col].down_start = True
 477                 # set the word
 478                 for i in range (len(word)):
 479                         self.data[row+i][col].occupied_down = True
 480                         self.data[row+i][col].char = word[i].upper ()
 481
 482
 483         # setting an across word
 484         def set_word_across (self, row, col, word):
 485                 # if the grid is frozen then abort
 486                 self.assert_unfrozen_grid ()
 487
 488                 # is the word length greater than totalcols - startcol?
 489                 if len(word) > self.cols - col:
 490                         raise TooLongWordException (word, len(word))
 491
 492                 # is the word intersecting any other word?
 493                 for i in range (len(word)):
 494                         # on the same row
 495                         if self.data[row][col+i].occupied_across is True:
 496                                 raise IntersectWordException (word, len(word))
 497                         # on a previous row except first row
 498                         if row > 0:
 499                                 # if not the first or last col
 500                                 if i > 0 and i < len(word) - 1:
 501                                         if self.data[row-1][col+i].occupied_across is True:
 502                                                 raise IntersectWordException (word, len(word))
 503                                 # if the previous row is the end of a down word
 504                                 if (self.data[row-1][col+i].occupied_down is True and
 505                                         self.data[row][col+i].occupied_down is False):
 506                                         raise IntersectWordException (word, len(word))
 507
 508                         # on a next row
 509                         if (row < (self.rows - 1)):
 510                                 # except the first and last letter check if there is
 511                                 # any across intersection
 512                                 if i > 0 and i < len (word) - 1:
 513                                         if self.data[row+1][col+i].occupied_across is True:
 514                                                 raise IntersectWordException (word, len(word))
 515                                 # if a down word is starting at any column below the
 516                                 # word
 517                                 if self.data[row+1][col+i].down_start is True:
 518                                         raise IntersectWordException (word, len(word))
 519
 520                 # also check the character beyond and before and after
 521                 if (col > 0 and (self.data[row][col-1].occupied_across is True or
 522                                         self.data[row][col-1].occupied_down is True)):
 523                         raise IntersectWordException (word, len(word))
 524                 if (col + len(word) < self.cols and
 525                                 (self.data[row][col+len(word)].occupied_across is True or
 526                                 self.data[row][col+len(word)].occupied_down is True)):
 527                         raise IntersectWordException (word, len(word))
 528
 529                 # set across start to true
 530                 self.data[row][col].across_start = True
 531
 532                 # set the word
 533                 for i in range (len(word)):
 534                         self.data[row][col+i].char = word[i].upper ()
 535                         self.data[row][col+i].occupied_across = True
 536
 537         # freeze the grid numbers etc.
 538         def freeze_grid (self):
 539                 # numbering
 540                 numbering = 1
 541                 # run through the grid
 542                 for row in range (self.rows):
 543                         for col in range (self.cols):
 544                                 # if grid is blank set the character to #
 545                                 if (self.data[row][col].occupied_across is False
 546                                         and self.data[row][col].occupied_down is False):
 547                                         self.data[row][col].char = "#"
 548                                 elif (self.data[row][col].across_start is True or
 549                                         self.data[row][col].down_start is True):
 550                                         self.data[row][col].numbered = numbering
 551                                         numbering += 1
 552
 553                 self.frozen_grid = True
 554
 555         # unfreeze the grid numbers etc.
 556         def unfreeze_grid (self):
 557                 # run through the grid
 558                 for row in range (self.rows):
 559                         for col in range (self.cols):
 560                                 self.data[row][col].numbered = 0
 561                                 if (self.data[row][col].occupied_across is False and
 562                                         self.data[row][col].occupied_down is False):
 563                                         self.data[row][col].char = '.'
 564
 565                 self.frozen_grid = False
 566
 567         # raise an exception if the grid is frozen
 568         def assert_unfrozen_grid (self):
 569                 if self.frozen_grid is True:
 570                         raise FrozenGridException
 571
 572         # raise an exception if the grid is NOT frozen
 573         def assert_frozen_grid (self):
 574                 if self.frozen_grid is False:
 575                         raise FrozenGridException
 576
 577         # reset the entire grid
 578         def reset_grid (self):
 579                 # run through the grid
 580                 for row in range (self.rows):
 581                         for col in range (self.cols):
 582                                 # re-initialize all data
 583                                 self.data[row][col].reset ()
 584
 585                 self.frozen_grid = False
 586
 587         # remove an across word at position
 588         def remove_word_across (self, row, col):
 589                 # if grid is frozen don't allow removal of word
 590                 self.assert_unfrozen_grid ()
 591
 592                 word, brow, bcol, l = self.get_word_across (row, col)
 593
 594                 # traverse from the beginning to end of the word and erase it
 595                 c = bcol
 596                 while c < self.cols:
 597                         if self.data[brow][c].occupied_across is True:
 598                                 self.data[brow][c].clear_across_data ()
 599                         else:
 600                                 break
 601                         c += 1
 602
 603         # remove a down word at position
 604         def remove_word_down (self, row, col):
 605                 # if grid is frozen don't allow removal of word
 606                 self.assert_unfrozen_grid ()
 607
 608                 word, brow, bcol, l = self.get_word_down (row, col)
 609                 # traverse from the beginn to end of the word and erase it
 610                 r = brow
 611                 while r < self.rows:
 612                         if self.data[r][bcol].occupied_down is True:
 613                                 self.data[r][bcol].clear_down_data ()
 614                         else:
 615                                 break
 616                         r += 1
 617
 618         # reveal/unreveal a word at position
 619         def reveal_word_across (self, row, col, revealed=True):
 620                 # set the revealed flag for the word at the position
 621                 word= self.get_word_across (row, col)
 622
 623                 c = word[2]
 624                 while c < self.cols:
 625                         if self.data[word[1]][c].occupied_across is True:
 626                                 self.data[word[1]][c].revealed = revealed
 627                         else:
 628                                 break
 629                         c += 1
 630
 631         # reveal/unreveal a word at position
 632         def reveal_word_down (self, row, col, revealed=True):
 633                 # set the revealed flag for the word at the position
 634                 word = self.get_word_down (row, col)
 635
 636                 r = word[1]
 637                 while r < self.rows:
 638                         if self.data[r][word[2]].occupied_down is True:
 639                                 self.data[r][word[2]].revealed = revealed
 640                         else:
 641                                 break
 642                         r += 1
 643
 644         # reveal/hide the entire solution by resetting revealed flag at all cells
 645         def reveal_solution (self, revealed=True):
 646                 # run through the grid and set revealed to False
 647                 for row in range (self.rows):
 648                         for col in range (self.cols):
 649                                 self.data[row][col].revealed = revealed
 650
 651         # clear the guesses for the board
 652         def clear_guesses (self):
 653                 # run through the grid and set the guesses to None
 654                 for row in range (self.rows):
 655                         for col in range (self.cols):
 656                                 self.data[row][col].guess = None
 657
 658         # verify the solution - return True if all guessed characters are correct
 659         # return False if some of them are wrong.
 660         # if the board is not completed as yet, raise a IncompleteSolutionException
 661         def is_solution_correct (self):
 662                 # run through the grid and check for each character in occupied cells
 663                 flag = True
 664                 for row in range (self.rows):
 665                         for col in range (self.cols):
 666                                 if (self.data[row][col].occupied_across is True or
 667                                         self.data[row][col].occupied_down is True):
 668                                         # if there is no guess at a particular location raise
 669                                         # the incomplete solution exception
 670                                         if not self.data[row][col].guess:
 671                                                 raise IncompleteSolutionException
 672                                         # if a character doesn't match, return False
 673                                         if self.data[row][col].char <> self.data[row][col].guess:
 674                                                 flag = False
 675
 676                 # finally return result
 677                 return flag
 678