pricehistory.py 文件源码

def price_history_frame(mkt_id, year, month):
    """Returns price history as a DataFrame"""
    url = _build_url('pricehistory/PriceHistory_GetData.cfm')
    data = dict(Market_ID=mkt_id, Month='{:02d}'.format(month), Year=year)
    response = requests.post(url=url, data=data)
    index_cols = [iem.DATE, iem.CONTRACT]
    kwargs = dict(header=0, parse_dates=[iem.DATE], index_col=index_cols)
    try:
        dfs = pd.read_html(response.text, **kwargs)
    except ValueError:
        dfs = [pd.DataFrame()]

    # Expect a singleton list
    assert len(dfs) == 1

    # Remove duplicates, if any
    df = dfs[0]
    if len(df.index.unique()) != len(df.index):
        df = df.groupby(level=df.index.names).first()

    return df