You will have two excel data files M3T1DO.xlsx and M3T1DI.xlsx with the dates and closing price of a stock. You need to update both existing excel data files for missing data in each files using the python program I have at the moment.

Requrements
We need to add a button to the UI. 
Once I click the button it should add the missing data in each other to both M3T1DI.xlsx and M3T1DO.xlsx. 
At the end of the code you will have two same exact excel files with two different names on it. 
We do not need any duplicate data in any of the files. 
The rest of  program should be able run using the updated file.