我正在阅读《掌握熊猫理财》一书,并为标准普尔500指数创建了以下数据框架:sp500 = pd.read_csv("sp500.csv", index='Symbol', usecols=[0, 2, 3, 7])
返回以下数据帧:
练习的一部分是使用以下代码显示只包含选择列的数据帧:
^{pr2}$
应生成以下数据帧:
运行代码时,出现以下错误:KeyError: '[1 2] not in index'
回溯---------------------------------------------------------------------------
KeyError Traceback (most recent call last)
in ()
----> 1 sp500[[1, 2]].head(3)
~/anaconda3/lib/python3.6/site-packages/pandas/core/frame.py in __getitem__(self, key)
1956 if isinstance(key, (Series, np.ndarray, Index, list)):
1957 # either boolean or fancy integer index
-> 1958 return self._getitem_array(key)
1959 elif isinstance(key, DataFrame):
1960 return self._getitem_frame(key)
~/anaconda3/lib/python3.6/site-packages/pandas/core/frame.p