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

# computes an average
def main():
    sum = 0
    count = 0
    # go until user says enough
    ans = "yes"
    while ans == "yes":
        # read number
        # we include the addition in the try in case the user
        # enters a string, quoted or not
        try:
            n = input("Enter number: ")
            # add it, increment count
            sum += n;
            count += 1
        except EOFError:    # on end of file, we're done; quit gracefully
            ans = "no"
        except (NameError, TypeError):  # non-number entered; complain
            print "You did not enter a number"            
        # ask if there is any more, unless you found an end of file
        # ans is "yes" unless we found an end of file
        if ans == "yes":
            # again, we do error checking; as this is for a string,
            # we only need to worry about an end of file
            try:
                ans = raw_input("Do you want to input another number (yes or no)? ")
            except EOFError:    # found end of file; quit gracefully
                ans = "no"
         
    # print average
    if count == 0:
        print "You didn't enter any numbers!"
    else:
        print "The average of the", count, "numbers you entered is", float(sum)/count


main()