def dfs_grid_recursive(grid, i, j, mark='X', free='.'):
    height = len(grid)
    width = len(grid[0])
    grid[i][j] = mark              # marquer passage
    for ni, nj in [(i + 1, j), (i, j + 1),
                   (i - 1, j), (i, j - 1)]:
        if 0 <= ni < height and 0 <= nj < width:
            if grid[ni][nj] == free:
                dfs_grid(grid, ni, nj)


# snip{ dfs-grid
Parses the config file path if passed with --config-file.
dataset/ETHPy150Open jilljenn/tryalgo/tryalgo/dfs.py/dfs_grid_recursive--crossover with--dataset/ETHPy150Open srsudar/eg/test/core_test.py/test_parses_long_config_file_correctly