AttributeError: Can only use .dt accessor with datetimelike values

这是我对从elastic拉出来的df里面一列时间进行操作的时候报错。

这是我的这部分的代码 

final_df['half_hour'] = final_df['raw_timestamp'].dt.floor(f'{conf.log_time_span}30min')

其实只需要转成datetime就可以了

final_df['raw_timestamp'] = pd.to_datetime(final_df['raw_timestamp'])
final_df['half_hour'] = final_df['raw_timestamp'].dt.floor(f'{conf.log_time_span}30min')