setup.py之后的Python ImportError

安装我的python项目setup.py并在终端中执行它后,我得到以下错误:

...
from ui.mainwindow import MainWindow
  File "/usr/local/lib/python2.7/dist-packages/EpiPy-0.1-py2.7.egg/epipy/ui/mainwindow.py", line 9, in 
    from model.sir import SIR
ImportError: No module named model.sir

...

我们假设我们的项目有以下结构cookies:

.
??? setup.py
??? src
    ??? a
    ?   ??? aa.py
    ?   ??? __init__.py
    ??? b
    ?   ??? bb.py
    ?   ??? __init__.py
    ??? __init__.py
    ??? main.py

文件: cookies/src/main.py

from a import aa

def main():
    print aa.get_aa()

文件 cookies/src/a/aa.py

from b import bb

def get_aa():
    return bb.get_bb()

文件: cookies/src/b/bb.py

def get_bb():
    return 'bb'

文件: cookies/setup.py

#!/usr/bin/env python

import os
import sys

try:
    from setuptools import setup, find_packages
except ImportError:
    raise ImportError("Install setup tools")

setup(
    name = "cookies",
    version = "0.1",
    author = "sam",
    description = ("test"),
    license = "MIT",
    keywords = "test",
    url = "asd@ads.asd",
    packages=find_packages(),
    classifiers=[
    """\
    Development Status :: 3 - Alpha
    Operating System :: Unix
    """
    ],
    entry_points = {'console_scripts': ['cookies = src.main:main',],},
)

如果我安装cookies作为root与$ python setup.py install和执行cookies我收到以下错误:ImportError: No module named b.我该如何解决这个问题.