You'll need to create an OAuth application to get the required CLIENT_ID and CLIENT_SECRET. Go here to do that. Application name and description can be anything. I set redirect uri to localhost:8000, just because it's required, but this won't be important. Then select 'Confidential Client' and then check 'Fantasy Sports'.
YAHOO_CLIENT_ID- Client ID for your OAuth applicationYAHOO_CLIENT_SECRET- Client Secret for your OAuth applicationYAHOO_LEAGUE_ID- League ID which can be obtained from the URL for your league (e.g. https://football.fantasysports.yahoo.com/f1/123456, where 123456 is the league id)
yfs = YahooFantasySports()
response = yfs.get_standings()