python - 将列数据移回 1 时出现 KeyError

Question

我正在使用循环神经网络根据之前的风力数据进行每小时的风力预测。我正在尝试使用 .shift 将我的数据移回 1 小时以生成此数据。我的 DateFrame 看起来像 [this][1] 我的代码是:

import numpy as np
import pandas as pd 
from pandas import DataFrame 

wind_p = [0, 0.03454225, 0.02062136, 0.00186715, 0.01517354, 0.0129046,  
0.02231125, 0.01492537, 0.09646542, 0.28444476]

Speed = [0, 2.25226244, 1.44078451, 0.99174488, 0.71179491, 0.92824542, 1.67776948, 2.96399534, 5.06257161, 7.06504245]

Date = ['2012-01-01 01:00:00' ,'2012-01-01 02:00:00', '2012-01-01 03:00:00', '2012-01-01 04:00:00', 
'2012-01-01 05:00:00', '2012-01-01 06:00:00', '2012-01-01 07:00:00',
'2012-01-01 08:00:00', '2012-01-01 09:00:00', '2012-01-01 10:00:00']

df = pd.DataFrame({'date':Date,'wind_P':wind_p,'Speed':Speed})
dates=[datetime.strptime(x,'%Y-%m-%d %H:%M:%S') for x in Date]


df['t']= [x for x in range(10)]
df['t+1'] = df[Speed].shift(-1)
print(df)

我得到的错误信息是:

KeyError                                  Traceback (most recent call last)
<ipython-input-1-bb88ddb20ff4> in <module>()
     18 
     19 df['t']= [x for x in range(10)]
---> 20 df['t+1'] = df[Speed].shift(-1)
     21 print(df)

~/anaconda3_501/lib/python3.6/site-packages/pandas/core/frame.py in __getitem__(self, key)
   1956         if isinstance(key, (Series, np.ndarray, Index, list)):
   1957             # either boolean or fancy integer index
-> 1958             return self._getitem_array(key)
   1959         elif isinstance(key, DataFrame):
   1960             return self._getitem_frame(key)

~/anaconda3_501/lib/python3.6/site-packages/pandas/core/frame.py in _getitem_array(self, key)
   2000             return self.take(indexer, axis=0, convert=False)
   2001         else:
-> 2002             indexer = self.loc._convert_to_indexer(key, axis=1)
   2003             return self.take(indexer, axis=1, convert=True)
   2004 

~/anaconda3_501/lib/python3.6/site-packages/pandas/core/indexing.py in _convert_to_indexer(self, obj, axis, is_setter)
   1229                 mask = check == -1
   1230                 if mask.any():
-> 1231                     raise KeyError('%s not in index' % objarr[mask])
   1232 
   1233                 return _values_from_object(indexer)

KeyError: '[0.         2.25226244 1.44078451 0.99174488 0.71179491 0.92824542\n 1.67776948 2.96399534 5.06257161 7.06504245] not in index'



Help with shifting the data in column `Speed` back by 1 step would be appreciated!

  [1]: /image/oANWb.jpg

Answer 1

In [114]: df['t+1'] = df['Speed'].shift(-1)
#  NOTE:                 ^     ^

In [115]: df
Out[115]:
                  date    wind_P     Speed  t       t+1
0  2012-01-01 01:00:00  0.000000  0.000000  0  2.252262
1  2012-01-01 02:00:00  0.034542  2.252262  1  1.440785
2  2012-01-01 03:00:00  0.020621  1.440785  2  0.991745
3  2012-01-01 04:00:00  0.001867  0.991745  3  0.711795
4  2012-01-01 05:00:00  0.015174  0.711795  4  0.928245
5  2012-01-01 06:00:00  0.012905  0.928245  5  1.677769
6  2012-01-01 07:00:00  0.022311  1.677769  6  2.963995
7  2012-01-01 08:00:00  0.014925  2.963995  7  5.062572
8  2012-01-01 09:00:00  0.096465  5.062572  8  7.065042
9  2012-01-01 10:00:00  0.284445  7.065042  9       NaN