why so many import error in the program

[aiwenzhu]

hi guys ,I'm new one in this project.
i got a mistake;
almost all of my program have import error like this:

from model.train_val import get_training_roidb, train_net
from model.config import cfg, cfg_from_file, cfg_from_list, get_output_dir, get_output_tb_dir
from datasets.factory import get_imdb
import datasets.imdb
every row has a red line.

why i change this to :
from lib.model.train_val import get_training_roidb, train_net
from lib.model.config import cfg, cfg_from_file, cfg_from_list, get_output_dir, get_output_tb_dir
from lib.datasets.factory import get_imdb
import lib.datasets.imdb
the red line is gone.

but run the demo wrong also