我认为您需要dt.hour
:
print (df.TIMESTAMP.dt.hour)
0 0
1 0
Name: TIMESTAMP, dtype: int64
df['hours'] = df.TIMESTAMP.dt.hour
print (df)
TIMESTAMP P_ACT_KW PERIODE_TARIF P_SOUSCR hours
0 2016-01-01 00:00:00 116 HC 250 0
1 2016-01-01 00:10:00 121 HC 250 0