Demo of McCabe complexity moving things into a separate function

mccabe_modernizer.py

def prepare_line_list(line):

    line_list = re.split("\s+", line)
    # Use of re.split adds an empty element to the list
    del line_list[len(line_list) - 1]

    # Add empty field if we don't have a middle name
    if len(line_list) is not 7:
        line_list.insert(3, "")

    # Remove "F13" if it's there, complain otherwise
    if line_list[5] == "F13":
        del line_list[5]
    else:
        bad_input('Fifth Field is not "F13".  Bad file?')

    return line_list


def main():
    for line in fileinput.input():

        line_list = prepare_line(line)

        for word in line_list[1:3]:
            word = word.capitalize()

        print "final line"
        print line_list