pandas - 如何在 Pandas 中将索引转换为日期时间？

Question

我有这样的索引

Index(['00:00:00', '00:15:00', '00:30:00', '00:45:00', '01:00:00', '01:15:00',
       '01:30:00', '01:45:00', '02:00:00', '02:15:00', '02:30:00', '02:45:00'],
      dtype='object', name='time') 

并需要将其转换为日期时间 %H:%M:%S 格式
我怎样才能改变它？

Answer 1

我认为你需要:

idx = pd.Index(['00:00:00', '00:15:00', '00:30:00', '00:45:00', '01:00:00', '01:15:00',
       '01:30:00', '01:45:00', '02:00:00', '02:15:00', '02:30:00', '02:45:00'],
      dtype='object', name='time') 

对于 DatetimeIndex需要一些日期，默认添加今天:

print (pd.to_datetime(idx))
DatetimeIndex(['2018-01-25 00:00:00', '2018-01-25 00:15:00',
               '2018-01-25 00:30:00', '2018-01-25 00:45:00',
               '2018-01-25 01:00:00', '2018-01-25 01:15:00',
               '2018-01-25 01:30:00', '2018-01-25 01:45:00',
               '2018-01-25 02:00:00', '2018-01-25 02:15:00',
               '2018-01-25 02:30:00', '2018-01-25 02:45:00'],
              dtype='datetime64[ns]', name='time', freq=None)

或者可以添加自定义日期:

print (pd.to_datetime('2015-01-01 ' + idx))
DatetimeIndex(['2015-01-01 00:00:00', '2015-01-01 00:15:00',
               '2015-01-01 00:30:00', '2015-01-01 00:45:00',
               '2015-01-01 01:00:00', '2015-01-01 01:15:00',
               '2015-01-01 01:30:00', '2015-01-01 01:45:00',
               '2015-01-01 02:00:00', '2015-01-01 02:15:00',
               '2015-01-01 02:30:00', '2015-01-01 02:45:00'],
              dtype='datetime64[ns]', freq=None)

另一种解决方案是创建 TimedeltaIndex :

print (pd.to_timedelta(idx))

TimedeltaIndex(['00:00:00', '00:15:00', '00:30:00', '00:45:00', '01:00:00',
                '01:15:00', '01:30:00', '01:45:00', '02:00:00', '02:15:00',
                '02:30:00', '02:45:00'],
               dtype='timedelta64[ns]', name='time', freq=None)