It seems that twp.yahooFinance has stopped working a couple of days ago. I've traced the issue and it seems to be with Yahoo finance :(.
The data api that was working for years is now not responding, essentially breaking the libraries that rely on it. Not only mine twp.yahooFinance module has stopped working, but also for example pandas-datareader (see errors in generated documentation).
This is of course utterly annoying. Unfortunately I can't fix it right away, as the not working part is on the Yahoos end. I only can wonder if this is a temporary glitch or if the functionality has been removed on purpose.
I'm sure it will get solved one way or another, in the worst case I'll need to migrate to a different data provider.