must be in python keep getting errors when running: please help

You are a volunteer member of an organization called the Friends of the Shenandoah River, which monitors water-quality issues in the Shenandoah Valley. Water quality data is gathered weekly at a number of sites along the river by various volunteers and the data is then uploaded to their website (http://fosr.org/data). You have been asked to create a computer program that can read the data files that have been uploaded to the site, and then display statistical calculations based on that data You'd like to implement the following functionality: 1. You want to give the user a choice of one of two files, "Turbidity.txt" and "LabpH.txt" which you will find attached. Each file has in the first row the name of the item being measured and then an unknown number of readings. If you ask the user to enter the name of the file, be sure upper or lower case doesn't matter. (Note: the lower) and upper) method converts the case of a string, e.g. if you print 'turbidity.txt.upper() you will get TURBIDITY.TXT' as output) Also, be sure you give a good message if the program can't find the file that the user requests. 2. You want to be able to read a file with any number of rows, but you won't know ahead of time how many rows of data will be in the file. You do know, however, that there will be no missing values, i.e. empty cells, in the data tables. (Hint: See chapter 6, or the lecture slides, on how to read from the file until the end of the file is reached. Which kind of loop will you need?) Your code may algorithmically look something like this