# Program to show interactive while loop
# Matt Bishop, May  4, 2009
# for ECS 10 Spring 2009

# computes an average
def main():
    # initialize
    sum = 0
    count = 0
    # get file name and open file
    try:
        inname = raw_input("Enter file name: ")
        infile = open(inname, "r")
    except EOFError:            # exit
        return
    except IOError as detail:   # couldn't open the file
        print detail
        return

    # if we get here, we have the file opened
    # read in its contents
    line = infile.readline()
    # process each line
    while line != "":
        # add number, increment count
        try:
            sum += int(line);
        except ValueError:       # not a number on the line
            print "Invalid number \"%s\"" % line
        else:                   # it worked; one more number
           count += 1
        # get next number
        line = infile.readline()

    # print average
    if count > 0:
        print "The average of the", count, "numbers you entered is", float(sum)/count
    else:
        print "No numbers entered!"

main()