loader.py 文件源码

def _load_raw_yahoo_data(indexes=None, stocks=None, start=None, end=None):
    """Load closing prices from yahoo finance.

    :Optional:
        indexes : dict (Default: {'SPX': '^SPY'})
            Financial indexes to load.
        stocks : list (Default: ['AAPL', 'GE', 'IBM', 'MSFT',
                                 'XOM', 'AA', 'JNJ', 'PEP', 'KO'])
            Stock closing prices to load.
        start : datetime (Default: datetime(1993, 1, 1, 0, 0, 0, 0, pytz.utc))
            Retrieve prices from start date on.
        end : datetime (Default: datetime(2002, 1, 1, 0, 0, 0, 0, pytz.utc))
            Retrieve prices until end date.

    :Note:
        This is based on code presented in a talk by Wes McKinney:
        http://wesmckinney.com/files/20111017/notebook_output.pdf
    """
    assert indexes is not None or stocks is not None, """
must specify stocks or indexes"""

    if start is None:
        start = pd.datetime(1990, 1, 1, 0, 0, 0, 0, pytz.utc)

    if start is not None and end is not None:
        assert start < end, "start date is later than end date."

    data = OrderedDict()

    if stocks is not None:
        for stock in stocks:
            logger.info('Loading stock: {}'.format(stock))
            stock_pathsafe = stock.replace(os.path.sep, '--')
            cache_filename = "{stock}-{start}-{end}.csv".format(
                stock=stock_pathsafe,
                start=start,
                end=end).replace(':', '-')
            cache_filepath = get_cache_filepath(cache_filename)
            if os.path.exists(cache_filepath):
                stkd = pd.DataFrame.from_csv(cache_filepath)
            else:
                stkd = DataReader(stock, 'yahoo', start, end).sort_index()
                stkd.to_csv(cache_filepath)
            data[stock] = stkd

    if indexes is not None:
        for name, ticker in iteritems(indexes):
            logger.info('Loading index: {} ({})'.format(name, ticker))
            stkd = DataReader(ticker, 'yahoo', start, end).sort_index()
            data[name] = stkd

    return data