python: check if a hostname is resolved

You can use socket.gethostbyname() for this:

>>> import socket
>>> socket.gethostbyname('google.com')
'74.125.224.198'
>>> socket.gethostbyname('foo')           # no host 'foo' exists on the network
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
socket.gaierror: [Errno 8] nodename nor servname provided, or not known

Your function might look like this:

def hostname_resolves(hostname):
    try:
        socket.gethostbyname(hostname)
        return 1
    except socket.error:
        return 0

Example:

>>> hostname_resolves('google.com')
1
>>> hostname_resolves('foo')
0