history_transaction.md

Group by and count transaction within a period

Source: https://stackoverflow.com/questions/47362530/python-pandas-group-datetimes-by-hour-and-count-row

df.date=pd.to_datetime(df.date)
df.groupby([pd.Grouper(key='date',freq='H'),df.station]).size().reset_index(name='count')
Out[235]: 
                 date station  count
0 2017-10-30 15:00:00       A      2
1 2017-10-31 07:00:00       A      1
2 2017-10-31 07:00:00       B      2