add a Grid helper class to assist with looking up clues

puz.py

@@ -305,17 +305,22 @@ def has_rebus(self):
         return self.rebus().has_rebus()
 
     def rebus(self):
-        return self.helpers.setdefault('rebus', Rebus(self))
+        if 'rebus' not in self.helpers:
+            self.helpers['rebus'] = Rebus(self)
+        return self.helpers['rebus']
 
     def has_markup(self):
         return self.markup().has_markup()
 
     def markup(self):
-        return self.helpers.setdefault('markup', Markup(self))
+        if 'markup' not in self.helpers:
+            self.helpers['markup'] = Markup(self)
+        return self.helpers['markup']
 
     def clue_numbering(self):
-        numbering = DefaultClueNumbering(self.fill, self.clues, self.width, self.height)
-        return self.helpers.setdefault('clues', numbering)
+        if 'clues' not in self.helpers:
+            self.helpers['clues'] = DefaultClueNumbering(self.fill, self.clues, self.width, self.height)
+        return self.helpers['clues']
 
     def blacksquare(self):
         return BLACKSQUARE2 if self.puzzletype == PuzzleType.Diagramless else BLACKSQUARE
@@ -506,7 +511,10 @@ def __init__(self, grid, clues, width, height):
                         'clue': clues[c],
                         'clue_index': c,
                         'cell': i,
-                        'len': self.len_across(i)
+                        'row': self.row(i),
+                        'col': self.col(i),
+                        'len': self.len_across(i),
+                        'dir': 'across',
                     })
                     c += 1
                 is_down = self.row(i) == 0 or is_blacksquare(grid[i - width])
@@ -516,7 +524,10 @@ def __init__(self, grid, clues, width, height):
                         'clue': clues[c],
                         'clue_index': c,
                         'cell': i,
-                        'len': self.len_down(i)
+                        'row': self.row(i),
+                        'col': self.col(i),
+                        'len': self.len_down(i),
+                        'dir': 'down'
                     })
                     c += 1
                 if c > lastc:
@@ -544,6 +555,50 @@ def len_down(self, index):
         return c + 1
 
 
+class Grid:
+    def __init__(self, grid, width, height):
+        self.grid = grid
+        self.width = width
+        self.height = height
+        assert len(self.grid) == self.width * self.height
+
+    def get_cell(self, row, col):
+        return self.grid[self.get_cell_index(row, col)]
+
+    def get_cell_index(self, row, col):
+        return row * self.width + col
+
+    def get_range(self, row, col, length, dir='across'):
+        if dir == 'across':
+            return self.get_range_across(row, col, length)
+        elif dir == 'down':
+            return self.get_range_down(row, col, length)
+        else:
+            assert False, "dir not one of 'across' or 'down'"
+
+    def get_range_across(self, row, col, length):
+        start = self.get_cell_index(row, col)
+        return self.grid[start:start+length]
+
+    def get_range_down(self, row, col, length):
+        return [self.grid[self.get_cell_index(row + i, col)] for i in range(length)]
+
+    def get_range_for_clue(self, clue):
+        return self.get_range(clue['row'], clue['col'], clue['len'], clue['dir'])
+
+    def get_string(self, row, col, length, dir='across'):
+        return ''.join(self.get_range(row, col, length, dir))
+
+    def get_string_across(self, row, col, length):
+        return ''.join(self.get_range_across(row, col, length))
+
+    def get_string_down(self, row, col, length):
+        return ''.join(self.get_range_down(row, col, length))
+
+    def get_string_for_clue(self, clue):
+        return ''.join(self.get_range_for_clue(clue))
+
+
 class Rebus:
     def __init__(self, puzzle):
         self.puzzle = puzzle

tests.py

@@ -23,6 +23,34 @@ def test_clue_numbering(self):
         self.assertEqual(len(p.clues), len(clues.across) + len(clues.down))
         self.assertTrue(len(p.clues) > 0)
 
+        a1 = clues.across[0]
+        self.assertEqual(a1['num'], 1)
+        self.assertEqual(a1['dir'], 'across')
+        self.assertEqual(a1['clue'], "Mary's pet")
+        self.assertEqual(a1['clue_index'], 0)
+        self.assertEqual(a1['cell'], 0)
+        self.assertEqual(a1['row'], 0)
+        self.assertEqual(a1['col'], 0)
+        self.assertEqual(a1['len'], 4)
+
+        self.assertEqual(a1['clue'], p.clues[a1['clue_index']])
+
+        d1 = clues.down[0]
+        self.assertEqual(d1['num'], 1)
+        self.assertEqual(d1['dir'], 'down')
+        self.assertEqual(d1['clue'], "Hit high in the air")
+        self.assertEqual(d1['clue_index'], 1)
+        self.assertEqual(d1['cell'], 0)
+        self.assertEqual(d1['row'], 0)
+        self.assertEqual(d1['col'], 0)
+        self.assertEqual(d1['len'], 4)
+
+        self.assertEqual(d1['clue'], p.clues[d1['clue_index']])
+
+        soln = puz.Grid(p.solution, p.width, p.height)
+        self.assertEqual('LAMB', soln.get_string_for_clue(a1))
+        self.assertEqual('LOFT', soln.get_string_for_clue(d1))
+
     def test_diagramless_clue_numbering(self):
         p = puz.read('testfiles/nyt_diagramless.puz')
         clues = p.clue_numbering()

tox.ini

@@ -9,6 +9,10 @@ description = run unit tests
 commands =
     python tests.py
 
+[testenv:unittest]
+description = quick run unit tests without installing package
+skip_install = true
+
 [testenv:lint]
 description = run flake8 on source code
 commands =