This function works correctly and is giving me the exact value of final_list when I am printing it. 
But when I decided to print final_list separately to check if the value is getting changed globally, I find out that the value of final_list is being changed locally
What to do so that final_list gets changed globally?
Use the keyword global in the function to make it a global variable.The changes within a function will be affected globally .
global variable
make these changes
global final_list in line 2 of your function.
As lists are mutable in Python. Don't add the line final_list = [ ] in your function and then run the code.
It will change the final_list.
