如何使用 datetime 删除重复的 python3 时间？

dates = pd.DatetimeIndex(['2017/06/01','2017/06/02','2017/06/02','2017/06/02','2017/06/03'])
dates
 DatetimeIndex(['2017-06-01', '2017-06-02', '2017-06-02', '2017-06-02',
   '2017-06-03'],
   dtype='datetime64[ns]', freq=None)
 
dup_ts = pd.Series(np.arange(5),index = dates)
dup_ts
 2017-06-01 0
 2017-06-02 1
 2017-06-02 2
 2017-06-02 3
 2017-06-03 4
 dtype: int32
 
dup_ts.index.is_unique
 False
dup_ts['2017-06-02']
 2017-06-02 1
 2017-06-02 2
 2017-06-02 3
 dtype: int32
 
grouped = dup_ts.groupby(level=0).mean()
grouped
 2017-06-01 0
 2017-06-02 2
 2017-06-03 4
 dtype: int32
 
dup_df = pd.DataFrame(np.arange(10).reshape((5,2)),index = dates )
dup_df
0   1
2017-06-01  0   1
2017-06-02  2   3
2017-06-02  4   5
2017-06-02  6   7
2017-06-03  8   9
grouped_df = dup_df.groupby(level=0).mean()##针对DataFrame
grouped_df