Python 2 Number Guess Game


I made a couple additions to the Python 2 Number Guess project while trying to follow its original style. Might do more, such as continuation of play. Any suggestions?

Number Guess
The program should do the following:

Roll user input number of dice.
Add the values of the roll.
Ask the user to guess a number.
Compare the user's guess to the total value.
Human wins if guess matches computer roll total.
from random import randint
from time import sleep

def get_user_guess():
  guess = int(raw_input("Enter guess: "))
  return guess

def get_number_of_dice():
  number_of_dice = int(raw_input("How many dice would you like to play with(1 to 9): "))
  return number_of_dice

def get_number_of_sides():
  number_of_sides = int(raw_input("How many sides would you like each die to have(3 to 20): "))
  return number_of_sides

def roll_dice(number_of_dice, number_of_sides):
  dice = []
  for roll in range(number_of_dice):
    dice.append(randint(1, number_of_sides))
  max_val = number_of_dice * number_of_sides
  print("The lowest possible roll is: %d" % number_of_dice)
  print("The highest possible roll is: %d" % max_val)
  guess = get_user_guess()
  if guess > max_val or guess < number_of_dice:
    print("Invalid Guess. Goodbye.")
    for roll in range(number_of_dice):
      print("Die {}: {}".format(roll+1, dice[roll]))
    total_roll = sum(dice)
    print("Total Roll: %d" % total_roll)
    if guess == total_roll:
      print("You win!!!")
      print("Sorry, you have lost.")
def play_dice_game():
  print("Playing Dice Game")
  number_of_dice = get_number_of_dice()
  if number_of_dice < 1 or number_of_dice > 9:
    print("Invalid number of dice. Goodbye.")
    number_of_sides = get_number_of_sides()
    if number_of_sides < 3 or number_of_sides > 20:
      print("Invalid number of sides. Goodbye.")
      roll_dice(number_of_dice, number_of_sides)