def find_first_key(hostname, known_hosts_files=['~/.ssh/known_hosts'], port=22):
    '''
    Look for first matching host key in a sequence of known_hosts files
    '''
    for f in known_hosts_files:
        x = load(f)
        try:
            entry = next(x.matching_keys(hostname, port))
            return entry
        except __HOLE__:
            pass
    return None
dataset/ETHPy150Open radssh/radssh/radssh/known_hosts.py/find_first_key