calculate the sum of the effective daily average temperatures-CodePudding

I'm new to python and I want to calculate the sum of the daily average temperatures on many hours and then append it to the dataframe e.g :

date	Temperature
2015-04-01 00:00:00	3.9
2015-04-01 01:00:00	2.10
2015-04-01 02:00:00	4.8
⋮	⋮
2015-10-31 23:00:00	2.16

I'm trying to get this output:

date	Temperature	averageT
2015-04-01 00:00:00	3.9	5
2015-04-01 01:00:00	2.10	5
2015-04-01 02:00:00	4.8	5
⋮	⋮
2015-10-31 23:00:00	2.16	7

CodePudding user response：

df['averageT'] = df.resample(rule='D', on='date').transform('mean')

CodePudding user response：

I used this as input data:

df = pd.DataFrame({
    'date': [pd.Timestamp('2015-04-01 00:00:00'),pd.Timestamp('2015-04-01 01:00:00'),pd.Timestamp('2015-04-01 02:00:00'),pd.Timestamp('2015-10-31 23:00:00')],
    'Temperature': [3.9, 2.1, 4.8, 2.16]
})

                 date  Temperature
0 2015-04-01 00:00:00         3.90
1 2015-04-01 01:00:00         2.10
2 2015-04-01 02:00:00         4.80
3 2015-10-31 23:00:00         2.16

Then use pd.Grouper to group the data day by day (if there is no data for a day, the mean will be NaN.

df['averageT'] = df.groupby(pd.Grouper(key='date', freq='1D'))['Temperature'].transform('mean')

print(df)

                 date  Temperature  averageT
0 2015-04-01 00:00:00         3.90      3.60
1 2015-04-01 01:00:00         2.10      3.60
2 2015-04-01 02:00:00         4.80      3.60
3 2015-10-31 23:00:00         2.16      2.16