def get_historical_info(symbol, from_dt=None, to_dt=None):

    if from_dt is None or to_dt is None:
        date_string = ''
    else:
        date_string = ('&a=%d&b=%d&c=%d&d=%d&e=%d&f=%d&g=d&ignore=.csv' %
                       (from_dt.month-1, from_dt.day, from_dt.year,
                        to_dt.month-1, to_dt.day, to_dt.year))

    yql = ('select * from csv where url="%s"'
           ' and columns="Date,Open,High,Low,Close,Volume,AdjClose"' %
           (HISTORICAL_URL + symbol + date_string))
    response = execute_yql_query(yql)
    results = __validate_response(response, 'row')
    # delete first row which contains column names
    del results[0]
    return results
build histograms of the coverage over each of the contigs
dataset/ETHPy150Open gurch101/StockScraper/stockretriever.py/get_historical_info--crossover with--dataset/ETHPy150Open CGATOxford/cgat/obsolete/pipeline_genomeassembly.py/buildCoverageOverRayContigs