How do I access netstat data in Python?

If you want to control the connection opened by a certain process you can use psutil:

>>> p = psutil.Process(1694)>>> p.name()'firefox'>>> p.connections()[connection(fd=115, family=2, type=1, local_address=('10.0.0.1', 48776), remote_address=('93.186.135.91', 80), status='ESTABLISHED'), connection(fd=117, family=2, type=1, local_address=('10.0.0.1', 43761), remote_address=('72.14.234.100', 80), status='CLOSING'), connection(fd=119, family=2, type=1, local_address=('10.0.0.1', 60759), remote_address=('72.14.234.104', 80), status='ESTABLISHED'), connection(fd=123, family=2, type=1, local_address=('10.0.0.1', 51314), remote_address=('72.14.234.83', 443), status='SYN_SENT')]

Internally psutil uses /proc.If you're interested in connections to/from a particular port number at system level you might take a look at how psutil implements it.

Edit: starting from psutil 2.1.0 you can also gather system-wide connections using net_connections():

>>> import psutil>>> psutil.net_connections()[pconn(fd=115, family=2, type=1, laddr=('10.0.0.1', 48776), raddr=('93.186.135.91', 80), status='ESTABLISHED', pid=1254), pconn(fd=117, family=2, type=1, laddr=('10.0.0.1', 43761), raddr=('72.14.234.100', 80), status='CLOSING', pid=2987), pconn(fd=-1, family=2, type=1, laddr=('10.0.0.1', 60759), raddr=('72.14.234.104', 80), status='ESTABLISHED', pid=None), pconn(fd=-1, family=2, type=1, laddr=('10.0.0.1', 51314), raddr=('72.14.234.83', 443), status='SYN_SENT', pid=None) ...]