Python Pandas - Index' 对象没有属性 'hour'
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Python Pandas - Index' object has no attribute 'hour'
提问by Runner Bean
I have a pandas dateframe and the following code works
我有一个Pandas日期框，以下代码有效
df['hour'] = df.index.hour
df['c'] = df['hour'].apply(circadian)
but i was trying to reduce the need to make a 'hour' coloumn, using the following code
但我试图使用以下代码减少制作“小时”列的需要
df['c'] = df.apply(lambda x: circadian(x.index.hour), axis=1)
but I get the error message
但我收到错误消息
AttributeError: ("'Index' object has no attribute 'hour'", u'occurred at index 2015-09-25 01:00:00')
anyone know how to do this?
有人知道怎么做吗？
回答by Nickil Maveli
Approach 1:
方法一：
Convert the DateTimeIndexto Seriesand use apply.
转换DateTimeIndex为Series并使用apply。
df['c'] = df.index.to_series().apply(lambda x: circadian(x.hour))
Approach 2:
方法二：
Use axis=0which computes along the row-index.
使用axis=0which 沿行索引计算。
df['c'] = df.apply(lambda x: circadian(x.index.hour), axis=0)
回答by piRSquared
solution
use the datetime accessor dt
解决方案
使用日期时间访问器dt
df['c'] = df.index.to_series().dt.hour.apply(circadian)
