ModuleNotFoundError: No module named 'utils.box_overlaps'

[YluXbei]

When I run the code python3 voxelnet_ros.py on unbuntu18.04,I get the issue

Traceback (most recent call last):
File "voxelnet_ros.py", line 17, in
from model import RPN3D
File "../voxelnet/model/init.py", line 12, in
from model.model import *
File "../voxelnet/model/model.py", line 11, in
from utils import *
File "../vpoxelnet/utils/init.py", line 10, in
from utils.box_overlaps import *
ModuleNotFoundError: No module named 'utils.box_overlaps'

I think maybe because there are some problem on cython ? But I`m so vegetable that I cant figure out what happen,could someone help me to solve this issue,thx.

[YluXbei]

actually its do have some problem on cython that python cant import the extension filename .pyx,in order to solve this issue,we should add
import pyximport
pyximport.install()
before import the .pyx module we need.