AttributeError: 'NoneType' object has no attribute 'dtypes'

Question

我正在尝试根据日期索引按升序对数据框的子集进行排序。当我运行排序功能时，只能通过指定轴代码运行s。当我添加 inplace=True 时，我收到错误消息：AttributeError Traceback (most recent call last) in ----> 1 daily_data.dtypes

AttributeError: 'NoneType' 对象没有属性 'dtypes'

如何在不删除 inplace=True 的情况下修复错误？

column_subset= ['date','from_municipality','from_municipality_number','to_municipality','to_municipality_number','count']
daily_data = df[column_subset]

daily_data = daily_data.set_index(pd.DatetimeIndex(daily_data['date']))
daily_data.drop(['date'], axis=1, inplace=True)
daily_data.replace(to_replace='*', value=np.nan, inplace=True)
daily_data.head()

daily_data = daily_data.sort_index(axis = 0, inplace=True) 

daily_data.dtypes

Answer 1

如果您使用 inplace=True，请不要将结果分配给它（它将是 None）：

daily_data.sort_index(axis=0, inplace=True)
daily_data.dtypes

AttributeError: 'NoneType' object has no attribute 'dtypes'

AttributeError: 'NoneType' object has no attribute 'dtypes'

python

attributeerror

pandas

nonetype

dtype