You can apply on entire df if you have only year,month and hour_minute columns like this
df.apply(lambda row: pd.to_datetime(''.join(row.values.astype(str)), format="%Y%m%d%H%M") ,axis=1)
Out[198]:
0 2015-11-05 00:10:00
1 2015-01-20 02:00:00
2 2015-11-05 04:05:00
3 2015-11-05 21:10:00
4 2015-10-21 23:59:00
dtype: datetime64[ns]
if there are other columns as well then just select the required columns then apply
df[['YEAR', 'MONTH', 'DAY', 'HOUR_MINUTE']].apply(lambda row: pd.to_datetime(''.join(row.values.astype(str)), format="%Y%m%d%H%M") ,axis=1)
Out[201]:
0 2015-11-05 00:10:00
1 2015-01-20 02:00:00
2 2015-11-05 04:05:00
3 2015-11-05 21:10:00
4 2015-10-21 23:59:00
dtype: datetime64[ns]
if you want new_column to be assigned to df then
df['new_column'] = df[['YEAR', 'MONTH', 'DAY', 'HOUR_MINUTE']].apply(lambda row: pd.to_datetime(''.join(row.values.astype(str)), format="%Y%m%d%H%M") ,axis=1)
df
Out[205]:
YEAR MONTH DAY HOUR_MINUTE new_column
0 2015 1 15 0010 2015-11-05 00:10:00
1 2015 1 2 0020 2015-01-20 02:00:00
2 2015 1 15 45 2015-11-05 04:05:00
3 2015 1 15 2110 2015-11-05 21:10:00
4 2015 10 21 2359 2015-10-21 23:59:00