'Returns the most recent bid/ask price for a ticker.'

def get_best_bid_ask(self, ticker):

    if (ticker in self.tickers):
        bid = self.tickers[ticker]['bid']
        ask = self.tickers[ticker]['ask']
        return (bid, ask)
    else:
        print(('Bid/ask    values    for    ticker    %s    are    not    available    from    the    PriceHandler.' % ticker))
        return (None, None)
