You can use psutil:
>>> import psutil
>>> p = psutil.Process(2549)
>>> p.name()
'proftpd: (accepting connections)'
>>> p.connections()
[connection(fd=1, family=10, type=1, local_address=('::', 21), remote_address=(), status='LISTEN')]
...To filter for listening sockets:
>>> [x for x in p.get_connections() if x.status == psutil.CONN_LISTEN]
[connection(fd=1, family=10, type=1, local_address=('::', 21), remote_address=(), status='LISTEN')]
>>>
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…