lucky unicorn fully working program, combining all components first version of fully working program, not yet tested for usability

lucky_unicorn_v1.py

# lucky unicorn fully working program, combining all components
# first version of fully working program, not yet tested for usability

import random


# function goes here
def int_check(question, low, high):
    valid = False
    while not valid:
        error = "Whoops! please enter a number between {}" \
                " and {}".format(low, high)
        try:
            response = int(input(question.format(low, high)))
            if low <= response <= high:
                return response
            else:
                print(error)
                print()

        except ValueError:
            print(error)


# main routine goes here
HOW_MUCH = 100  # constant representing the amount spent by user
ZEBRA_HORSE_PAYOUT = 0.5
UNICORN_PAYOUT = 5
GAME_FEE = 1
MAX_AMOUNT = 10

# ask how much the user wants to play with
user_balance = int_check("How much money would you like"
                         " to play with?", GAME_FEE, MAX_AMOUNT)

keep_playing = ""
while not keep_playing:
    # balancing the odds - now only 10% chance to get unicorn
    tokens = ["donkey", "donkey", "donkey", "horse", "horse", "horse",
              "zebra", "zebra", "zebra", "unicorn"]

    # generate random choice taken off list
    token = random.choice(tokens)
    print("\nyou got a {}".format(token))

    # adjust user_balance correctly for given token
    if token == "donkey":
        user_balance -= 1
        print("sorry, you didn't win anything this round")
    elif token == "zebra" or token == "horse":
        user_balance += ZEBRA_HORSE_PAYOUT - 1
        print("sorry, you only won ${:.2f}".format(ZEBRA_HORSE_PAYOUT))
    elif token == "unicorn":
        user_balance += UNICORN_PAYOUT - 1
        print("congratulations you won ${:.2f}".format(UNICORN_PAYOUT))

    # check and report user_balance, giving option to play again if at least $1
    if user_balance >= GAME_FEE:
        print("you have ${:.2f} left to play with".format(user_balance))
        keep_playing = input("press <enter> to play another round or"
                             " press 'Q' to quit\n")
    else:
        print("you don't have enough credit for another round")
        keep_playing = "Q"


# farewells the player at the end of the game
print("\nyou are leaving with a balance of ${:.2f}"
      "\nthanks for playing. goodbye".format(user_balance))