Sending EMsg.ClientMicroTxnAuthorize in python

[Valvoja]

Has anyone got an idea how to send this in python? I have no idea. I think I have to wrap it around Msg() or MsgProto(), but I don't know how to mimic this in python:

let payload = new ByteBuffer(12, ByteBuffer.LITTLE_ENDIAN);
payload.writeInt64(973858335);
payload.writeInt32(1);
steamClient.send({ msg: Steam.EMsg.ClientMicroTxnAuthorize, proto: null }, payload.buffer, (header, body))