Question

我有一个专栏，我已经使用pandas将其转换为datetime，现在它的格式为datetime64。

LOCAL_TIME_ON 
2014-06-21 15:32:09
2014-06-07 20:17:13

我想将小时提取到新列。我发现作品的唯一内容就在下面，但是，我得到了一个SettingWithCopyWarning。有没有人能以更清洁的方式做到这一点？

TRIP_INFO_TIME['TIME_HOUR'] = pd.DatetimeIndex(TRIP_INFO_TIME['LOCAL_TIME_ON']).hour.astype(int)

C:\Program Files (x86)\JetBrains\PyCharm Community Edition 2016.1.4\helpers\pydev\pydevconsole.py:1: SettingWithCopyWarning: 
A value is trying to be set on a copy of a slice from a DataFrame.
Try using .loc[row_indexer,col_indexer] = value instead

See the caveats in the documentation: http://pandas.pydata.org/pandas-docs/stable/indexing.html#indexing-view-versus-copy
  '''

Answer 1

试试这个：

TRIP_INFO_TIME['TIME_HOUR'] = TRIP_INFO_TIME['LOCAL_TIME_ON'].dt.hour

从datetime64 [ns]变量中提取小时

1 个答案: