ImportError: No module named _version

[scheung38]

Hi I am trying to use demo.app:

from _version import __version__

parser.add_argument('--version', action='version', version='%%(prog)s %s' % __version__)

init.py:

from distutils.core import setup

setup(name='demoapp.py',
      version='1.0',
      description='Create a demoapp',
      author='Sebastian Cheung',
      author_email='scheung@yahoo.com',
      url='http://github.com/scheung38',
      license='BSD',
      scripts=['demoapp.py']
     )

But output is:
python demoapp.py --version
Traceback (most recent call last):
File "demoapp.py", line 6, in
from _version import version
ImportError: No module named _version