James, I'm sorry I didn't show it but using socket.gethostname() as the source of hostname works just fine, too.

import socket
>>> hostname = socket.gethostname()
>>> hostname
'harj.local'
>>> socket.getaddrinfo(hostname, None)
[(<AddressFamily.AF_INET6: 30>, <SocketKind.SOCK_DGRAM: 2>, 17, '', ('fe80::8d8:1de3:dfa:e34c%en1', 0, 0, 5)), (<AddressFamily.AF_INET6: 30>, <SocketKind.SOCK_STREAM: 1>, 6, '', ('fe80::8d8:1de3:dfa:e34c%en1', 0, 0, 5)), (<AddressFamily.AF_INET: 2>, <SocketKind.SOCK_DGRAM: 2>, 17, '', ('10.0.1.7', 0)), (<AddressFamily.AF_INET: 2>, <SocketKind.SOCK_STREAM: 1>, 6, '', ('10.0.1.7', 0))]

I don't know what to tell you other than the behavior you are seeing is almost certainly not a Python issue.  There are many other ways to explore host names, like using the "host" command line utility or "netstat".  But that is all beyond the scope of this bug tracker.  If you need more assistance, perhaps ask on one of the StackExchange forums or Apple lists.  I'm going to close this issue; if you are able to isolate what appears to be a Python issue here, please feel free to re-open this.  Good luck!