import datetime as dt
from gs_quant.markets.baskets import Basket
from gs_quant.session import Environment, GsSession
client = 'CLIENT ID'
secret = 'CLIENT SECRET'
GsSession.use(Environment.PROD, client_id=client, client_secret=secret)
basket = Basket.get('GSMBXXXX') # substitute input with any identifier for a basket
basket.get_close_price_for_date(dt.date(2021, 1, 7))