[Distutils] How does distuils/setuptools determine script directory?

[Bryce Hendrix]

I have a python Windows install I built from source, which when 
installed does not create a Scripts directory. When I install setuptools 
the easy_install executable is put in Lib/site-packages rather than 
Scripts. All other eggs also put their scripts in the site-packages 
directory.

How does distutils and setuptools decide where to install scripts to by 
default?

Bryce