I have a pandas data frame from this CSV file. 
I have several of these files that I'm combining into one large file. I need to iterate over the player column, and if one cell partially matches the corresponding CPTN cell, then I need to update the Pos value for the player cell containing CPTN to be CPTN + '(POS)'.
The final results would look something like this:
Bryce Mitchell WR
Bryant Koback RB
Bryant Koback CPTN CPTN (RB)
Bryce Mitchell CPTN CPTN (WR)
Here is a spreadsheet to test: Test Sheet