#
#  Average the values entered by the user.  A blank line will be used to mark 
#  the end of input.
#

#
#  Initialize count and total to 0.
#
count = 0
total = 0

#
#  Read the first value from the user.
#
line = input("Enter a number (blank line to quit): ")

#
#  While the value entered by the user is not a blank line...
#
while line != "":
  #
  #  Convert the value entered by the user into a number
  #
  num = float(line)

  # 
  #  Add the current value to the total so far.
  #
  total = total + num

  #
  #  Count that another value was added to the total.
  #
  count = count + 1

  #
  #  Read the next value from the user.
  #
  line = input("Enter a number (blank line to quit): ")

if count > 0:
  #
  #  Compute and display the average.
  #
  print("The average of those values is", total / count)
else:
  #  Report that the average could not be displayed.
  print("No values were entered, so the average could not be displayed.")