I am writing a program in Python 3 that will take data from a csv file, make adjustments to it and write the new data to a csv file that will be named by the user.
I
Command line options are stored in sys.argv. You may want to check this:
http://docs.python.org/3/library/sys.html?highlight=argv#sys.argv
Beside, if you need more complex command-line argument parsing and deciding your program logic based on that, you should try argparse