'Returns the most recent actual timestamp for a given ticker'

def get_last_timestamp(self, ticker):

    if (ticker in self.tickers):
        timestamp = self.tickers[ticker]['timestamp']
        return timestamp
    else:
        print(('Timestamp    for    ticker    %s    is    not    available    from    the    %s.' % (ticker, self.__class__.__name__)))
        return None
