假设df看起来像

print(df)

             date_col
0 2018-07-25 11:14:00
1 2018-08-26 11:15:00
2 2018-07-29 11:17:00
#convert from string to datetime
df['date_col'] = pd.to_datetime(df['date_col']) 

#to get date only
print(df['date_col'].dt.date)
0    2018-07-25
1    2018-08-26
2    2018-07-29

#to get time:
print(df['date_col'].dt.time)

0    11:14:00
1    11:15:00
2    11:17:00
#to get hour and minute
print(df['date_col'].dt.strftime('%H:%M'))
0    11:14
1    11:15
2    11:17