Question

我正在尝试从时间序列pandas DataFrame中删除假日数据。我正在遵循的说明处理DatetimeSeries并使用函数set_index（）将此DatetimeSeries应用于DataFrame，从而产生没有假期的时间序列。这个set_index（）函数对我不起作用。看看代码......

{data_day.tail()}
Open    High    Low Close   Volume
Date                    
2018-05-20  NaN NaN NaN NaN 0.0
2018-05-21  2732.50 2739.25 2725.25 2730.50 210297692.0
2018-05-22  2726.00 2741.75 2721.50 2738.25 179224835.0
2018-05-23  2731.75 2732.75 2708.50 2710.50 292305588.0
2018-05-24  2726.00 2730.50 2705.75 2725.00 312575571.0

from pandas.tseries.holiday import USFederalHolidayCalendar

from pandas.tseries.offsets import CustomBusinessDay

usb = CustomBusinessDay(calendar=USFederalHolidayCalendar())

usb

<CustomBusinessDay>

data_day_No_Holiday = pd.date_range(start='9/7/2005', end='5/21/2018', freq=usb)
data_day_No_Holiday

DatetimeIndex(['2005-09-07', '2005-09-08', '2005-09-09', '2005-09-12',
               '2005-09-13', '2005-09-14', '2005-09-15', '2005-09-16',
               '2005-09-19', '2005-09-20',
               ...
               '2018-05-08', '2018-05-09', '2018-05-10', '2018-05-11',
               '2018-05-14', '2018-05-15', '2018-05-16', '2018-05-17',
               '2018-05-18', '2018-05-21'],
              dtype='datetime64[ns]', length=3187, freq='C')


data_day.set_index(data_day_No_Holidays, inplace=True)

----------------------------------------------------------------------

ValueError                                Traceback (most recent call last)
<ipython-input-118-cf7521d08f6f> in <module>()
----> 1 data_day.set_index(data_day_No_Holidays, inplace=True)
      2 # inplace=True tells python to modify the original df and to NOT create a new one.

~/anaconda3/lib/python3.6/site-packages/pandas/core/frame.py in set_index(self, keys, drop, append, inplace, verify_integrity)
   3923         index._cleanup()
   3924 
-> 3925         frame.index = index
   3926 
   3927         if not inplace:

~/anaconda3/lib/python3.6/site-packages/pandas/core/generic.py in __setattr__(self, name, value)
   4383         try:
   4384             object.__getattribute__(self, name)
-> 4385             return object.__setattr__(self, name, value)
   4386         except AttributeError:
   4387             pass

pandas/_libs/properties.pyx in pandas._libs.properties.AxisProperty.__set__()

~/anaconda3/lib/python3.6/site-packages/pandas/core/generic.py in _set_axis(self, axis, labels)
    643 
    644     def _set_axis(self, axis, labels):
--> 645         self._data.set_axis(axis, labels)
    646         self._clear_item_cache()
    647 

~/anaconda3/lib/python3.6/site-packages/pandas/core/internals.py in set_axis(self, axis, new_labels)
   3321             raise ValueError(
   3322                 'Length mismatch: Expected axis has {old} elements, new '
-> 3323                 'values have {new} elements'.format(old=old_len, new=new_len))
   3324 
   3325         self.axes[axis] = new_labels

ValueError: Length mismatch: Expected axis has 4643 elements, new values have 3187 elements

这个过程似乎对另一个程序员来说很漂亮。

是否有人建议进行数据类型转换或将DatetimeIndex应用于DataFrame的函数，这将导致丢弃未在data_day_No_Holiday DatetimeIndex中表示的所有数据行（假日）？

谢谢，如果我发现任何格式错误或者我遗漏了任何相关信息，请告诉我......

Answer 1

使用reindex：

from pandas.tseries.holiday import USFederalHolidayCalendar

from pandas.tseries.offsets import CustomBusinessDay

usb = CustomBusinessDay(calendar=USFederalHolidayCalendar())

data_day_No_Holiday = pd.date_range(start='1/1/2018', end='12/31/2018', freq=usb)

data_day  = pd.DataFrame({'Values':np.random.randint(0,100,365)},index = pd.date_range('2018-01-01', periods=365, freq='D'))

data_day.reindex(data_day_No_Holiday).dropna()'

输出（头）：

            Values
2018-01-02      38
2018-01-03       1
2018-01-04      16
2018-01-05      43
2018-01-08      95

在时间序列中使用set_index来消除DataFrame中的假日数据行

1 个答案: