I have two data files and both have different periods of datetime.
As you can see below, the first 'Date' is from 2013-10-14 to 2015-11-25, and the second 'Date' is from 2014-01-01 to 2015-11-27.
If I want to make the date from 2013-10-14 to 2015-11-27 and fill the blank as np.nan, what do I have to do in the code?
If you know how to do it or any idea, please let me know.
dvv : Date
2013-10-14 -0.038875
2013-10-15 -0.038875
2013-10-16 -0.038875
2013-10-17 -0.038875
2013-10-18 -0.038875
2015-11-21 0.081939
2015-11-22 -0.097986
2015-11-23 -0.096201
2015-11-24 -0.033913
2015-11-25 -0.050553
Name: dvv, Length: 773, dtype: float64
Stations Sensor EL GL Pressure Temp EC Barometa
Date
2014-01-01 JRee3 S11 NaN NaN NaN NaN NaN NaN
2014-01-02 JRee3 S11 NaN NaN NaN NaN NaN NaN
2014-01-02 JRee3 S11 NaN NaN NaN NaN NaN NaN
2014-01-04 JRee3 S11 NaN NaN NaN NaN NaN NaN
2014-01-05 JRee3 S11 NaN NaN NaN NaN NaN NaN
... ... ... ... ... ... ... ...
2015-11-23 JRee3 S11 213.46 202.21 99.83 14.22 105.0 1008.13
2015-11-24 JRee3 S11 213.36 202.31 99.73 14.22 105.0 1008.36
2015-11-25 JRee3 S11 213.34 202.33 99.71 14.22 105.0 1004.40
2015-11-26 JRee3 S11 213.30 202.37 99.67 14.22 105.0 1003.13
2015-11-27 JRee3 S11 213.24 202.44 99.61 14.21 105.0 1011.00
[696 rows x 8 columns]
CodePudding user response:
You can generate new dates this way (replace periods with sufficient number):
days = pd.date_range('14/10/2013', periods=365, freq='D')
You will get something like this which you can add to your dataframe:
DatetimeIndex(['2013-10-14', '2013-10-15', '2013-10-16', '2013-10-17',
'2013-10-18', '2013-10-19', '2013-10-20', '2013-10-21',
'2013-10-22', '2013-10-23',
...
'2014-10-04', '2014-10-05', '2014-10-06', '2014-10-07',
'2014-10-08', '2014-10-09', '2014-10-10', '2014-10-11',
'2014-10-12', '2014-10-13'],
dtype='datetime64[ns]', length=365, freq='D')
CodePudding user response:
Assuming you have no missing values in the dates, then you can simply exploit pandas.date_range
and an outer join.
Toy example below:
import pandas as pd
dates1 = pd.date_range('2013-10-14', '2015-11-25', freq='D')
dates2 = pd.date_range('2014-01-01', '2015-11-27', freq='D')
df1 = pd.DataFrame(data=[1]*len(dates1), index=dates1, columns=['var'])
df2 = pd.DataFrame(data=[2]*len(dates2), index=dates2, columns=['var'])
df1.merge(df2, left_index=True, right_index=True, how='outer')