您可以使用assign + abs，然后使用groupby + agg:

You can use a assign + abs, followed by groupby + agg:

df = (df.assign(Data_Value=df['Data_Value'].abs())
       .groupby(['Day'])['Data_Value'].agg([('Min' , 'min'), ('Max', 'max')])
       .add_prefix('Day'))

df 
       DayMin  DayMax
Day                  
01-01       0     115
01-02       0      79