about the path of extensive modules

[huzhenghui37]

with my experience 
when i install the wxPython  the installer put all things in the 
python\Lib\site-packages\
and from the source code "import wxpthon.wx" i know how import the modules
when i install the py2exe  the installer also put all things in the 
python\Lib\site-packages\

so i wonder the information about the method of  modules path management 
in python.
and if i write my own package of modules how to use (say, install) in python
thanks