Thanks for the quick support! I placed dsmr.py in the folder, but this results in the error:
Traceback (most recent call last): File "/usr/lib/python3.4/asyncio/tasks.py", line 237, in _step result = next(coro) File "/home/homeassistant/.homeassistant/custom_components/sensor/dsmr.py", line 135, in connect_and_reconnect reader_factory()) File "/srv/homeassistant/lib/python3.4/site-packages/dsmr_parser/clients/protocol.py", line 50, in create_tcp_dsmr_reader dsmr_version, telegram_callback, loop=None) File "/srv/homeassistant/lib/python3.4/site-packages/dsmr_parser/clients/protocol.py", line 28, in create_dsmr_protocol dsmr_version) NotImplementedError: ('No telegram parser found for version: %s', '5')