Add obligated algo for columns, still missing something

board.py

@@ -149,31 +149,68 @@ class Board:
         self.__compute_possible_values_from_columns()
 
     def compute_obligated_in_each_line(self):
-        """Find obligated values per for every number.
+        """Find obligated values per line for every number.
 
         Go through each line. For each square, go through numbers 1 to 9. If
         the number is in the square's values but not in the values of the rest
         of the squares in the line then the square should take that number.
         """
 
-        self.__debug("++++++")
+        self.__debug("compute_obligated_in_each_line")
 
-        for line_index, line in enumerate(self.lines):
-            for square_index, square in enumerate(line):
+        for line_id, line in enumerate(self.lines):
+            self.__debug(f"Line n°{line_id}")
+            for square_id, square in enumerate(line):
+                self.__debug(f"    square n°{square_id}, {square.values}")
                 # Create an empty set to store the other square's values.
                 other_values = set()
-                for other_square_index in range(9):
-                    if other_square_index != square_index:
+                for other_square_id in range(9):
+                    # ignore current square
+                    if other_square_id != square_id:
+                        # update other_values with values of other squares
                         other_values = other_values.union(
-                            line[other_square_index].values
+                            line[other_square_id].values
                         )
 
-                self.__debug(other_values)
+                self.__debug(f"    other values: {other_values}")
 
                 for number in range(1, 10):
-                    if str(number) in square.values and number not in other_values:
-                        self.__debug(number)
-                        self.lines[line_index][square_index].values = {str(number)}
+                    if str(number) in square.values and \
+                       str(number) not in other_values:
+                        self.__debug(f"    {number}")
+                        self.lines[line_id][square_id].values = {str(number)}
+
+    def compute_obligated_in_each_column(self):
+        """Find obligated values per column for every number.
+
+        Go through each column. For each square, go through numbers 1 to 9. If
+        the number is in the square's values but not in the values of the rest
+        of the squares in the column then the square should take that number.
+        """
+
+        self.__debug("compute_obligated_in_each_column")
+
+        for col_id, column in enumerate(self.columns):
+            self.__debug(f"Column n°{col_id}")
+            for square_id, square in enumerate(column):
+                self.__debug(f"    square n°{square_id}, {square.values}")
+                # Create an empty set to store the other square's values.
+                other_values = set()
+                for other_square_id in range(9):
+                    # ignore current square
+                    if other_square_id != square_id:
+                        # update other_values with values of other squares
+                        other_values = other_values.union(
+                            column[other_square_id].values
+                        )
+
+                self.__debug(f"    other values: {other_values}")
+
+                for number in range(1, 10):
+                    if str(number) in square.values and \
+                       str(number) not in other_values:
+                        self.__debug(f"    {number}")
+                        self.columns[col_id][square_id].values = {str(number)}
 
     def create_squares(self):
         """Make each square of the board a Square object."""
@@ -194,14 +231,15 @@ class Board:
     def discard_with_grids(self):
         """Remove impossible values in squares, by discarding from grids."""
 
-        for square in self.squares:
-            self.__debug(square.values)
-            self.__debug(self.grids[square.grid_id])
+        self.__debug("discard_with_grids")
+        for square_index, square in enumerate(self.squares):
+            self.__debug(f"    square n°{square_index}: {square.values}")
+            self.__debug(f"    values in grid: {self.grids[square.grid_id]}")
             if len(square.values) > 1:
                 for value in self.grids[square.grid_id]:
                     if value in square.values:
                         square.values.discard(value)
-            self.__debug(square.values)
+            self.__debug(f"    square n°{square_index}: {square.values}")
 
     def intersect_lines_and_columns(self):
         """Remove impossible values from possibilities in lines and columns.

main.py

@@ -70,7 +70,7 @@ def main():
         "47..5....\n"
     )]
 
-    for string in strings:
+    for string in strings[2:-3]:
         iterations = 0
         while '.' in string:
             iterations += 1
@@ -87,11 +87,13 @@ def iterate_board(string):
     """
 
     board = Board(string, debug=False)
+    print(f"New board:\n{board}")
     board.compute_possible_values()
     board.intersect_lines_and_columns()
     board.create_squares()
     board.discard_with_grids()
     board.compute_obligated_in_each_line()
+    board.compute_obligated_in_each_column()
     print(f"New board:\n{board}")
 
     return board.get_new_board()