Pandas：无法将 <class 'pandas.tseries.index.DatetimeIndex'> 类型转换为时间戳
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Pandas: Cannot convert type <class 'pandas.tseries.index.DatetimeIndex'> to Timestamp
提问by yuqli
I got the following error message when trying to slicing a pandas dataframe using labels.
尝试使用标签切片 Pandas 数据框时收到以下错误消息。
triggerDate = dat.loc[dat.Close <= threshold[0]][:1].index
cutDate= triggerDate.shift(1, 'd')
dat.truncate(before=triggerDate, after=cutDate)
TypeError: Cannot convert input [DatetimeIndex(['2010-05-05'], dtype='datetime64[ns]', name=u'Date', freq=None)] of type to Timestamp
类型错误：无法将输入 [DatetimeIndex(['2010-05-05'], dtype='datetime64[ns]', name=u'Date', freq=None)] 类型转换为时间戳
I am confused why datetimeIndex object cannot be used to slice this pandas dataframe here, because from the documentation on truncatingfunction, this should work? Why do I still need to convert datetimeIndex to Timestamp?
我很困惑为什么不能使用 datetimeIndex 对象在这里切片这个 Pandas 数据帧，因为从截断函数的文档来看，这应该有效吗？为什么我仍然需要将 datetimeIndex 转换为 Timestamp？
So I am guessing I probably miss some details here? Any help would be appreciated. Thanks!
所以我猜我可能会错过一些细节？任何帮助，将不胜感激。谢谢！
And here is the code and output of my sample dat:
这是我的示例数据的代码和输出：
type(dat)
class 'pandas.core.frame.DataFrame'
类'pandas.core.frame.DataFrame'
dat.head(5)
Open High Low Close Volume Adj Close Cash Position
Date
2010-05-03 13.18 13.49 13.18 13.30 106416800 10.747104 11.7 9988.3
2010-05-04 13.07 13.08 12.75 12.85 123207400 10.383480 0.0 0.0
2010-05-05 12.32 12.70 11.59 12.34 198525600 9.971373 0.0 0.0
2010-05-06 12.17 12.51 10.59 11.78 237094700 9.518863 0.0 0.0
2010-05-07 11.95 11.97 10.95 11.51 261066500 9.300689 0.0 0.0
triggerDate
DatetimeIndex(['2010-05-05'], dtype='datetime64[ns]', name=u'Date', freq=None)
DatetimeIndex(['2010-05-05'], dtype='datetime64[ns]', name=u'Date', freq=None)
type(triggerDate)
class 'pandas.tseries.index.DatetimeIndex'
类'pandas.tseries.index.DatetimeIndex'
type(cutDate)
class 'pandas.tseries.index.DatetimeIndex'
类'pandas.tseries.index.DatetimeIndex'
回答by jezrael
I think yous need [0]for convert DatetimeIndexas array with one value to scalar:
我认为您需要[0]将DatetimeIndex具有一个值的数组转换为标量：
triggerDate = dat.loc[dat.Close <= threshold[0]][:1].index[0]
Or better:
或更好：
triggerDate = dat.index[dat.Close <= threshold[0]][0]
