def construct_futures_symbols(
        symbol, start_year=2010, end_year=2014
    ):
    """
    Constructs a list of futures contract codes 
    for a particular symbol and timeframe.
    """
    futures = []
    # March, June, September and 
    # December delivery codes
    months = 'HMUZ' 
    for y in range(start_year, end_year+1):
        for m in months:
            futures.append("%s%s%s" % (symbol, m, y))
    return futures