我正在尝试使用 python 构建一个用于优化金融投资组合的程序。我想出了一个关键错误:日期。这是发生关键错误的部分:
#create a dataframe to store the adjusted close price of the stocks
df = pd.DataFrame()
#store the adjusted close price of the stock into the df
for stock in assets:
df[stock] = web.DataReader(stock, data_source='yahoo', start= stockStartDate , end = today)['Adj Close']
这是错误信息:
KeyError Traceback (most recent call last)
/usr/local/lib/python3.7/dist-packages/pandas/core/indexes/base.py in get_loc(self, key, method, tolerance)
2897 try:
-> 2898 return self._engine.get_loc(casted_key)
2899 except KeyError as err:
pandas/_libs/index.pyx in pandas._libs.index.IndexEngine.get_loc()
pandas/_libs/index.pyx in pandas._libs.index.IndexEngine.get_loc()
pandas/_libs/hashtable_class_helper.pxi in pandas._libs.hashtable.PyObjectHashTable.get_item()
pandas/_libs/hashtable_class_helper.pxi in pandas._libs.hashtable.PyObjectHashTable.get_item()
KeyError: 'Date'
上述异常是以下异常的直接原因:
KeyError Traceback (most recent call last)
6 frames
/usr/local/lib/python3.7/dist-packages/pandas/core/indexes/base.py in get_loc(self, key, method, tolerance)
2898 return self._engine.get_loc(casted_key)
2899 except KeyError as err:
-> 2900 raise KeyError(key) from err
2901
2902 if tolerance is not None: