Let's say we want to use libc's ntohl function.
First, we must load libc.so:
>>> from ctypes import *
>>> libc = cdll.LoadLibrary('libc.so.6')
>>> libc
<CDLL 'libc.so.6', handle baadf00d at 0xdeadbeef>
Then, we get the function object:
>>> ntohl = l...