将 Pandas 时间戳转换为时间（寻找比 .apply 更快的东西）
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/33000660/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
Converting Pandas Timestamp to just the time (looking for something faster than .apply)
提问by SpicyClubSauce
So if I have a timestamp in pandas as such:
因此，如果我在 Pandas 中有这样的时间戳：
Timestamp('2014-11-07 00:05:00')
How can I create a new column that just has the 'time' component?
如何创建一个只有“时间”组件的新列？
So I want
所以我想要
00:05:00
Currently, I'm using .applyas shown below, but this is slow (my dataframe is a couple million rows), and i'm looking for a faster way.
目前，我正在使用.apply如下所示，但这很慢（我的数据帧有几百万行），我正在寻找一种更快的方法。
df['time'] = df['date_time'].apply(lambda x: x.time())
Instead of .apply, I tried using .astype(time), as I noticed .astypeoperations can be faster than .apply, but that apparently doesn't work on timestamps (AttributeError: 'Timestamp' object has no attribute 'astype')... any ideas?
相反.apply，我尝试使用.astype(time)，因为我注意到.astype操作可能比 快.apply，但这显然不适用于时间戳（AttributeError: 'Timestamp' object has no attribute 'astype'）......有什么想法吗？
