Raspberry Pi Motor Driver Board

i follow the all instructions on wiki page of Rpi Motor Driver Board v1.0

but there is no PiSoftPwm file

Traceback (most recent call last):
File “motor.py”, line 6, in
from PiSoftPwm import *
ImportError: No module named PiSoftPwm

  error  :cry:  :cry:  :cry: