Find the path from top left to bottom right of array of numbers with the lowest possible sum and return the sum along this path.  minpathsum ...     1, 3, 1, ...     1, 5, 1, ...     4, 2, 1, ...  7  minpathsum ...     1, 0, 5, 6, 7, ...     8, 9, 0, 4, 2, ...     4, 4, 4, 5, 1, ...     9, 6, 3, 1, 0, ...     8, 4, 3, 2, 7, ...  20  minpathsumNone Traceback most recent call last: ... TypeError: The grid does not contain the appropriate information  minpathsum Traceback most recent call last: ... TypeError: The grid does not contain the appropriate information  fillrow2, 2, 2, 1, 2, 3 3, 4, 5
def min_path_sum(grid: list) -> int:
    """
    Find the path from top left to bottom right of array of numbers
    with the lowest possible sum and return the sum along this path.
    >>> min_path_sum([
    ...     [1, 3, 1],
    ...     [1, 5, 1],
    ...     [4, 2, 1],
    ... ])
    7

    >>> min_path_sum([
    ...     [1, 0, 5, 6, 7],
    ...     [8, 9, 0, 4, 2],
    ...     [4, 4, 4, 5, 1],
    ...     [9, 6, 3, 1, 0],
    ...     [8, 4, 3, 2, 7],
    ... ])
    20

    >>> min_path_sum(None)
    Traceback (most recent call last):
        ...
    TypeError: The grid does not contain the appropriate information

    >>> min_path_sum([[]])
    Traceback (most recent call last):
        ...
    TypeError: The grid does not contain the appropriate information
    """

    if not grid or not grid[0]:
        raise TypeError("The grid does not contain the appropriate information")

    for cell_n in range(1, len(grid[0])):
        grid[0][cell_n] += grid[0][cell_n - 1]
    row_above = grid[0]

    for row_n in range(1, len(grid)):
        current_row = grid[row_n]
        grid[row_n] = fill_row(current_row, row_above)
        row_above = grid[row_n]

    return grid[-1][-1]


def fill_row(current_row: list, row_above: list) -> list:
    """
    >>> fill_row([2, 2, 2], [1, 2, 3])
    [3, 4, 5]
    """

    current_row[0] += row_above[0]
    for cell_n in range(1, len(current_row)):
        current_row[cell_n] += min(current_row[cell_n - 1], row_above[cell_n])

    return current_row


if __name__ == "__main__":
    import doctest

    doctest.testmod()
