gistfile1.txt

def first_location_match(channel, locations):
    import os.path
    for x in locations:
        if os.path.exists(x):
            channel.send(x)
            break
    else:
        channel.send(None)
    
if __name__ == "__main__":
    import execnet
    gw = execnet.makegateway()
    ch = gw.remote_exec(first_location_match,
                        locations = ['/sbin/service', '/usr/sbin/service'])
    print "matched location:", ch.receive()