want to improve simple python code

Question

i am new to python programming. This is code that i want to improve

# Critter Caretaker
# A virtual pet to care for

class Critter(object):
    """A virtual pet"""
    def __init__(self, name, hunger = 0, boredom = 0):
        self.name = name
        self.hunger = hunger
        self.boredom = boredom

    def __pass_time(self):
        self.hunger += 1
        self.boredom += 1

    @property
    def mood(self):
        unhappiness = self.hunger + self.boredom
        if unhappiness < 5:
            m = "happy"
        elif 5 <= unhappiness <= 10:
            m = "okay"
        elif 11 <= unhappiness <= 15:
            m = "frustrated"
        else:
            m = "mad"
        return m

    def talk(self):
        print("I'm", self.name, "and I feel", self.mood, "now.\n")
        self.__pass_time()

    def eat(self, food = 4):
        print("Brruppp.  Thank you.")
        self.hunger -= food
        if self.hunger < 0:
            self.hunger = 0
        self.__pass_time()

    def play(self, fun = 4):
        print("Wheee!")
        self.boredom -= fun
        if self.boredom < 0:
            self.boredom = 0
        self.__pass_time()

    def __str__(self):
        rep = "Attribut value is\n"
        rep += str(self.hunger) + "\n" + str(self.boredom) + "\n"
        return rep


def main():
    crit_name = input("What do you want to name your critter?: ")
    crit = Critter(crit_name)

    choice = None  
    while choice != "0":
        print \
        ("""
        Critter Caretaker

        0 - Quit
        1 - Listen to your critter
        2 - Feed your critter
        3 - Play with your critter
        """)

        choice = input("Choice: ")
        print()

        # exit
        if choice == "0":
            print("Good-bye.")

        # listen to your critter
        elif choice == "1":
            crit.talk()

        # feed your critter
        elif choice == "2":
            crit.eat()

        # play with your critter
        elif choice == "3":
            crit.play()

        # secret option
        elif choice == "!":
            print(crit)

        # some unknown choice
        else:
            print("\nSorry, but", choice, "isn't a valid choice.")

main()
("\n\nPress the enter key to exit.")

You see it is a puppet that show his mood and search of you to feed and play with him. Every time puppet talk, eat or play counter pass_time add 2 level up. Attribute food and fun have always the same number that directly affects mood. I want to make that user can enter amount of food and time that can affect mood of puppet. Why i cant do this

    def eat(self, food):
        print("Brruppp.  Thank you.")
        self.hunger -= food
        if self.hunger < 0:
            self.hunger = 0
        self.__pass_time()

    def play(self, fun):
        print("Wheee!")
        self.boredom -= fun
        if self.boredom < 0:
            self.boredom = 0
        self.__pass_time()

and this

        choice = input("Choice: ")
        print()

        # exit
        if choice == "0":
            print("Good-bye.")

        # listen to your critter
        elif choice == "1":
            crit.talk()

        # feed your critter
        elif choice == "2":
            food = int(input("How much food?: "))

            crit.eat()

        # play with your critter
        elif choice == "3":
            fun = int(input("How much time?: "))

            crit.play()

        # secret option
        elif choice == "!":
            print(crit)

        # some unknown choice
        else:
            print("\nSorry, but", choice, "isn't a valid choice.")

Answer 1

You seem to be almost there if I understand your question right. Lets use the eat function as an example. You want to pass the food variable to the class function to use. If you want you can also add validation to check if that value entered is a number.

elif choice == "2":
    food = int(input("How much food?: "))
    crit.eat(food) # pass food in as a parameter