from datetime import datetime
import pandas as pd

def same_day(date_string):
return datetime.strptime(date_string, "%m/%d/%Y %H:%M:%S").strftime('%m-%d')

df = pd.read_csv('/home/kk/Desktop/JUHU sit.csv', index_col=[0],parse_dates=[0], usecols=[0,1,2])
********calculate per day
print (df.index.strftime('%d%m%H'))
print (df.groupby([df.index.strftime('%d%m%H')]).mean())

#****** exporting in CSV format
df.reset_index().to_csv('/home/kk/Desktop/JUHUAvg.csv')