sniffer in python

[billiejoex]

Hi!
I made a little, simple program that sends strings over an ICMP packet.
The source here:
http://billiejoex.altervista.org/a1.txt

Now all I need is create a simple network sniffer able to sniff the ICMP 
packets and print  the strings on the screen.
A useful library known in a lot of other programming languages is 'libcap' 
(winpcap for win32 platforms).
For python exist a porting called pcapy:
http://oss.coresecurity.com/projects/pcapy.html
...that I'd like to use BUT... all the examples reported on the sites don't 
works!!
Is there someone who has already created a network sniffer in python?
It shouldn't be too much difficult...

Best regards