CODE EXAMPLE FOR PYTHON

how to use group by in python to get 15 mins candle data from 1 min candle

df.head()
Out[7]: 
                       OPEN    HIGH     LOW   CLOSE  VOLUME 
DATE_TIME                                                   
1997-02-03 09:04:00  3046.0  3048.5  3046.0  3047.5      505
1997-02-03 09:05:00  3047.0  3048.0  3046.0  3047.0      162
1997-02-03 09:06:00  3047.5  3048.0  3047.0  3047.5       98
1997-02-03 09:07:00  3047.5  3047.5  3047.0  3047.5      228
1997-02-03 09:08:00  3048.0  3048.0  3047.5  3048.0      136