human
I wrote the below code

    _NO_DEFAULT.check(regtype)
    _NO_DEFAULT.check(port)
    port = socket.htons(port)
    if (not txtRecord):
        (txtLen, txtRecord) = (1, '\x00')
    else:
        (txtLen, txtRecord) = _string_to_length_and_void_p(txtRecord)
    @_DNSServiceRegisterReply
    def _callback(sdRef, flags, errorCode, name, regtype, domain, context):
        if (callBack is not None):
            callBack(sdRef, flags, errorCode, name.decode(), regtype.decode(), domain.decode())
    _global_lock.acquire()
    try:
        sdRef = _DNSServiceRegister(flags, interfaceIndex, name, regtype, domain, host, port, txtLen, txtRecord, _callback, None)
    finally:
        _global_lock.release()
    sdRef._add_callback(_callback)
    return sdRef

What's a good function header?
 ... Here's a good function header?
assistant
#Here's a good function header.

def DNSServiceRegister(flags=0, interfaceIndex=kDNSServiceInterfaceIndexAny, name=None, regtype=_NO_DEFAULT, domain=None, host=None, port=_NO_DEFAULT, txtRecord='', callBack=None):