how to import a 'zip' file to my .py

when i use http://github.com/joshthecoder/tweepy-examples ,

i find :

import tweepy

in the appengine\oauth_example\handlers.py

but i can't find a tweepy file or tweepy's 'py' file, except a tweepy.zip file,

i don't think this is right,cauz i never import a zip file,

i find this in app.py:

import sys
sys.path.insert(0, 'tweepy.zip')

why ?

how to import a zip file..

thanks

updated

a.py :

import sys
sys.path.insert(0, 'b.zip')

import b
print b

b.zip:

b file
   |-----__init__.py
   |-----c.py

c.py:

cc='ccccc'

the error is :

> "D:\Python25\pythonw.exe"  "D:\zjm_code\a.py" 
Traceback (most recent call last):
  File "D:\zjm_code\a.py", line 9, in <module>
    import b
ImportError: No module named b

updated2

it is ok now ,

the error's reason is : i rename b.rar to b.zip