I’m looking for duplicated reservation ID’s and then attempting to delete them from the spreadsheet. This is not working as it should. Where did I go wrong?

I tried using
dataRange = file1[~file1[‘Reservation ID’].isin(file2[‘Reservation ID’])]

file1 = file1.drop(file1.index[dataRange.index])

I expected a spreadsheet with nothing in it. What I got was a spreadsheet with the duplicated data.