Finding the delta of two unmatched dataframes in pandas-CodePudding

Having 2 Data Frames with readings at 2 different times as:

DF1

       Sensor ID    Reference Pressure     Sensor Pressure
0         013677                100.15               93.18
1         013688                101.10               95.23
2         013699                100.87               93.77
...          ...                  ...                  ...

And

DF2

       Sensor ID    Reference Pressure     Sensor Pressure
0         013688                120.01              119.43
1         013677                118.93              118.88
2         013699                120.05              118.85
...          ...                  ...                  ...

What would be the optimal way of creating a third Dataframe, that contains the difference between those readings, given that the "Sensor ID" values order does not match between the two dataframes?

CodePudding user response：

Pandas has this beautiful feature where it automatically aligns on indices. So we can use that to solve your problem:

df1.set_index("Sensor ID").sub(df2.set_index("Sensor ID"))

           Reference Pressure  Sensor Pressure
Sensor ID                                     
13677                  -18.78           -25.70
13688                  -18.91           -24.20
13699                  -19.18           -25.08