Error of "No module named xxx"

$ ./newrc_staf.py
Traceback (most recent call last):
  File "./newrc_staf.py", line 12, in
    from release import NightlyRelease
  File "/rootfs/git/newrc_staf_py/release/__init__.py", line 11, in
    from tools import losetup
ImportError: No module named tools

Solution:
Create corresponding __init__.py under import directories.