Once you do the above change then you will have to subtract the averaged blank value from individual columns i.e., AVERGAEIF the label in the second row is named as BLK. AVERAGEIF is a function is excel, there should be something similar in python as well.
Blanked Data = Value - Average(BLK)
In the sample table, usually blank values are labelled as BLK
In excel:
B2 of Blanked Data ='LOESS Data'!B2-AVERAGE('LOESS Data'!$AG2;'LOESS Data'!$AO2;'LOESS Data'!$AW2)
Here AG, AO and AW are the columns with the value obtained from blank wells.
Broken down from #3. From there: