Ask HN: Which developer conferences in Europe are worth attending?

Biggest Python conference is EuroPython (https://ep2019.europython.eu/) but it was in July so you missed that one...

There is PyCon in almost each country. I am volunteering at PyCon SK (https://pycon.sk/), but it will be in March next year.

You can make it to PyCon PL (https://pl.pycon.org/2019/en/), PyCon UK (https://2019.pyconuk.org/) in September in the past I have been on both and can recommend to visit.