Passing Objects Between functions?

Question

I am new to programming in python and, I started writing a simple text based adventure game. I came across a problem when passing an object from one function to another. Here is my code:

import random
import time
num = random.randint(0,2)
xp1 = random.randint(1,2)
class player:
    def __init__ (self, name, health, strength, defense, potion, xp, level):
        self.__health = health
        self.__strength = strength
        self.__defense = defense
        self.__name = name
        self.__potion = potion
        self.__xp = xp
        self.__level = level
        def getName(self):
            return self.__name

        def getHealth(self):
            return self.__health

        def getStrength(self):
            return self.__strength

        def getDefense(self):
            return self.__defense

        def getPotion(self):
            return self.__potion

        def getXP(self):
            return self.__xp

        def getLevel(self):
            return self.__level

        def setHealth(self):
            self.__health = 10

        def setLevel(self):
            self.__level = 1

        def subHealth(self, num):
            self.__health -= num

        def subPotion(self):
            self.__potion -= 1
            return self.__health

        def addPotion(self, num1):
            self.__potion += num1

        def addHealth(self):
            self.__health +=2

        def addStrength(self):
            self.__strength += 1

        def addDefense(self):
            self.__defense += 1

        def addXP(self):
            self.__xp += xp1

        def addLevel(self):
            self.__level += 1
            self.__addHealth += 1
            self.__defense += 1
            self.__strength += 1

    def battle(enemy, player1, name1):
        player1 = player(name1, player1.getHealth(), player1.getStrength(), player1.getDefense(), player1.getPotion(), player1.getXP(), player1.getLevel())
        enemy = player('Dongus', enemy.getHealth(), enemy.getStrength(), enemy.getDefense(), enemy.getPotion(), enemy.getXP(), enemy.getLevel())
        s = 0
        while s == 0:
            time.sleep(1)
            attack =int(input("Type 1 to attack, type 2 to use a potion."))
            if attack == 1:
                time.sleep(1)
                print("Dongus's health is", enemy.subHealth(num))
                print("Dongus hit you and your health is now at", player1.subHealth(num-player1.getDefense()))
            elif attack == 2:
                time.sleep(1)
                print("You used a potion.")
                player1.addHealth(), player1.subPotion()
                if player1.getHealth() > 10:
                    player1.setHealth()
                    print("Dongus hit you and your health is now at", player1.subHealth(num-player1.getDefense()))
            if enemy.getHealth()<=0:
                print("Congratulations, you won! You recieved", xp1, "xp!")
                player.addXP()
                s = 2
    def main():
        name1 = input("What would you like your name to be?")
        time.sleep(1)
        print("Hello,", name1, "you are on a quest to save otis from the evil Dongus. You must slay him, or Otis will poop.")
        time.sleep(2)
        player1 = player(name1, 10, 2, 1, 0, 0, 1)
        enemy = player('Dongus', 8, 4, 0, 0, 0, 0)
        print("Your stats are, health:", player1.getHealth(), "strength:", player1.getStrength(), "and defense:", player1.getDefense())
        time.sleep(2)
        print("Fight!")
        pick = input("You found a health potion! Press 'p' to pick it up.")
        p = 0
        while p == 0:
            if pick == "p":
                print("You added a potion to your inventory.")
                player1.addPotion(1)
                p = 2
            else:
                print("You have no potions, you should probably pick this one up.")
                player1.addPotion(1)
                p = 2
        battle(enemy, player1, name1)
        if self.__getXP() == 1:
            print("You leveled up. You are now level 2.")
            player1.addLevel()
            print("Your stats are, health:", player1.getHealth(), "strength:", player1.getStrength(), "and defense:", player.getDefense())       
        loot1 = int(input("Type ''1'' to loot the enemy chest."))
        if loot1 == 1:
            print("You recieved two potions!")
            player1.__addPotion(2)
        enemy.setHealth(10)
        battle(enemy, player1, name1)

main()

Now the problem is when I run the game, I get to a point where I type "1" to attack the enemy, but it says, for some reason, that after attacking the enemy, the enemies health is at "None". This is the same case when the enemy attacks player1, it says player1's health is at "None". I assume that "None" is the default value in python 3.4.1, so my thinking is that the player1's object from def main() are not being transferred over to def battle() and I cannot see the reason why this is happening. I most likely am missing something here, or it is something I do not already know about Python that is causing the issue. Does anybody know what I can do to fix this, and why it is doing this?

BTW some of the terms I am using may be wrong, so please correct me if they are... I have only been coding for 2 weeks :p.

Thanks!!!

Answer 1

First, received not recieved

2nd yes, If you have a Python function that does not return a value, the result is None

# dummy will return "Positive" or None
def dummy(x):
    if X > 0:
        return "Positive"

So, you probably want to change

def subHealth(self, num):
        self.__health -= num

to

def subHealth(self, num):
        self.__health -= num
        return self.__health

Your question re: the "player" classes from def main() are not being transferred over to def battle() does not really make sense to me.

But, I see that in the first 2 lines of battle, you are replacing the formal parameters player1 and enemy with local variables, this seems like odd usage in your program.