pandas 'NaTType' 对象没有属性 'days'
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/32269676/
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
'NaTType' object has no attribute 'days'
提问by Ruggero Turra
I have a column in my dataset which represents a date in ms and sometimes its values is nan(actually my columns is of type strand sometimes its valus is 'nan'). I want to compute the epoch in days of this column. The problem is that when doing the difference of two dates:
我的数据集中有一列表示以毫秒为单位的日期，有时它的值是nan（实际上我的列是类型str，有时它的值是'nan'）。我想计算本专栏的天数。问题是在做两个日期的差异时：
(pd.to_datetime('now') - pd.to_datetime(np.nan)).days
if one is nanit is converted to NaTand the difference is of type NaTTypewhich hasn't the attribute days.
如果是，nan则将其转换为NaT，并且差异是NaTType没有属性的类型days。
In my case I would like to have nanas a result.
就我而言，我希望nan结果如此。
Other approach I have tried: np.datetime64cannot be used, since it cannot take as argument nan. My data cannot be converted to intsince intdoesn't have nan.
我尝试过的其他方法：np.datetime64不能使用，因为它不能作为参数nan。我的数据无法转换为，int因为int没有nan.
回答by EdChum
It will just work even if you filter first:
即使您先过滤它也会起作用：
In [201]:
df = pd.DataFrame({'date':[dt.datetime.now(), pd.NaT, dt.datetime(2015,1,1)]})
df
Out[201]:
date
0 2015-08-28 12:12:12.851729
1 NaT
2 2015-01-01 00:00:00.000000
In [203]:
df.loc[df['date'].notnull(), 'days'] = (pd.to_datetime('now') - df['date']).dt.days
df
Out[203]:
date days
0 2015-08-28 12:12:12.851729 -1
1 NaT NaN
2 2015-01-01 00:00:00.000000 239
回答by alif
For me upgrading to pandas 0.20.3 from pandas 0.19.2 helped resolve this error.
对我来说，从 pandas 0.19.2 升级到 pandas 0.20.3 有助于解决这个错误。
pip install --upgrade pandas
