ack to 2306DataProgramming Q1. Implement a function getCustomerList that takes as argument filename to read the file and return it as a nested list, where each element is a list of [, , ] The filename argument doesn't contain the extension (e. input"), your program must automatically add the "txt" extension. If the file doesn't exist, the getCustomerList function will print the message: "Error! not found." and should return None. Save & Run Load History 1 2 def getCustomerlist(filename): 3 #write code to check if file exist and return List/None 4 pass 5 6 Activity: 1 File (L.90) Question in Context