use yahoo's fantasy API to download fantasy team / roster data
authenticating against the yahoo api is quite easy using the yahoo_oauth package. my understanding is that yahoo no longer supports OAuth 1 flow - you'll need to use OAuth2, and https requests for all resources.
query.py is what I threw together to pull down 9 years worth of roster data for my league. the league keys are specific to our leagues, but that dictionary of gameids is generic for fantasy baseball. might be useful given that the official yahoo documentation doesn't have those ids after 2012.