在 pandas 日期时间列中查找值之间的中点，并根据中点制作开始和结束时间段列

Question

这是我的代码设置：

import pandas as pd
    
    df = {'Datetime':  ['2020-12-01 00:00:00', '2020-12-01 01:00:00','2020-12-01 02:00:00',
                        '2020-12-01 03:00:00', '2020-12-01 04:00:00' , '2020-12-01 05:00:00' ,
                        '2020-12-01 06:00:00' , '2020-12-01 09:00:00' , '2020-12-01 12:00:00' ,
                        '2020-12-01 18:00:00' , '2020-12-02 00:00:00'
                       ]
           
            }
    
    df = pd.DataFrame(df , columns = ['Datetime'])
    
    df["Datetime"] = pd.to_datetime(df['Datetime'])
    
    df

生成具有以下形式的数据框：

    Datetime
0   2020-12-01 00:00:00
1   2020-12-01 01:00:00
2   2020-12-01 02:00:00
3   2020-12-01 03:00:00
4   2020-12-01 04:00:00
5   2020-12-01 05:00:00
6   2020-12-01 06:00:00
7   2020-12-01 09:00:00
8   2020-12-01 12:00:00
9   2020-12-01 18:00:00
10  2020-12-02 00:00:00

我想要做的是找到值之间的中点并在数据框中创建两个新列。两个新列是“开始时间”和“结束时间”。 “开始时间”是该时间与上一时间（如果存在）之间的中点。 “结束时间”是那个时间和下一个时间（如果存在的话）之间的中点。如果不存在则使用当前时间。

这是我希望代码生成的内容：

    Datetime    Start Time  End Time
0   2020-12-01 00:00:00     2020-12-01 00:00:00     2020-12-01 00:30:00
1   2020-12-01 01:00:00     2020-12-01 00:30:00     2020-12-01 01:30:00
2   2020-12-01 02:00:00     2020-12-01 01:30:00     2020-12-01 02:30:00
3   2020-12-01 03:00:00     2020-12-01 02:30:00     2020-12-01 03:30:00
4   2020-12-01 04:00:00     2020-12-01 03:30:00     2020-12-01 04:30:00
5   2020-12-01 05:00:00     2020-12-01 04:30:00     2020-12-01 05:30:00
6   2020-12-01 06:00:00     2020-12-01 05:30:00     2020-12-01 07:30:00
7   2020-12-01 09:00:00     2020-12-01 07:30:00     2020-12-01 10:30:00
8   2020-12-01 12:00:00     2020-12-01 10:30:00     2020-12-01 15:00:00
9   2020-12-01 18:00:00     2020-12-01 15:00:00     2020-12-01 21:00:00
10  2020-12-02 00:00:00     2020-12-02 21:00:00     2020-12-02 00:00:00

如果您能帮助解决这个问题，我们将不胜感激。

Answer 1

可以用shift计算中点得到连续行的时间差，除以2得到Start Time。然后，只需 shift(-1) 一行得到 End Time:

df['Start Time'] = (df['Datetime'] + (df['Datetime'].shift(1) - df['Datetime']) / 2).fillna(df['Datetime'])
df['End Time'] = (df['Start Time'].shift(-1)).fillna(df['Datetime'])
df
Out[1]: 
              Datetime          Start Time            End Time
0  2020-12-01 00:00:00 2020-12-01 00:00:00 2020-12-01 00:30:00
1  2020-12-01 01:00:00 2020-12-01 00:30:00 2020-12-01 01:30:00
2  2020-12-01 02:00:00 2020-12-01 01:30:00 2020-12-01 02:30:00
3  2020-12-01 03:00:00 2020-12-01 02:30:00 2020-12-01 03:30:00
4  2020-12-01 04:00:00 2020-12-01 03:30:00 2020-12-01 04:30:00
5  2020-12-01 05:00:00 2020-12-01 04:30:00 2020-12-01 05:30:00
6  2020-12-01 06:00:00 2020-12-01 05:30:00 2020-12-01 07:30:00
7  2020-12-01 09:00:00 2020-12-01 07:30:00 2020-12-01 10:30:00
8  2020-12-01 12:00:00 2020-12-01 10:30:00 2020-12-01 15:00:00
9  2020-12-01 18:00:00 2020-12-01 15:00:00 2020-12-01 21:00:00
10 2020-12-02 00:00:00 2020-12-01 21:00:00 2020-12-02 00:00:00

在 pandas 日期时间列中查找值之间的中点，并根据中点制作开始和结束时间段列

Finding the midpoint between values in a pandas datetime column and making a start and end time period column based on the midpoint

dataframe

python-3.x

python-datetime

pandas

pandas-timeindex