def fill(grid: dict, value: str, start=(0, 0), stop=(0, 0)):
    'Using product allows for flatter loops.'
    from itertools import product
    for coord in product(range(start[0], stop[0]), range(start[1], stop[1])):
        grid[coord] = value
Using product allows for flatter loops.
def fill(grid: dict, value: str, start=(0, 0), stop=(0, 0)):
    
    from itertools import product
    for coord in product(range(start[0], stop[0]), range(start[1], stop[1])):
        grid[coord] = value