def solve_boards(file, guess, verbose):
"""Solve each board in a text file."""
if verbose:
print('#', 'solved?', 'board', 'strategy', sep='\t')
exclude = None if guess else [999]
with open(file, 'r') as boards:
for line in boards:
line = line.strip()
if not line or line.startswith('#'):
continue
board = Sudoku(line)
n = board.num_solved()
hardest = board.solve(exclude=exclude)
try:
board.verify()
except:
print('*** ERROR:', line)
Sudoku(line).solve(exclude=exclude, verbose=True)
break
if verbose:
print(board.num_solved() - n, 'TRUE' if board.solved() else 'FALSE',
line, hardest, sep='\t')
