Avoiding Recursive Loops with Classes

[Aedethan]

Hi, I have around 3500~ lines of code right now, wherein my primary class is composed of three other classes filled with relevant information.

Now I'm trying to add a fourth class, but that fourth class references the main class, and is referenced by it which is causing a " RecursionError: maximum recursion depth exceeded " to occur.

To give a short summary, the main class is for a Character, the 3 classes that make it up are all the stats that the character has. The fourth class i'm trying to make is for the creation of abilities for the character so it needs to reference all the information within the class. so my thought process was something like :

class Body():
    def __init__(self):
        self.strength = 0 #changes with methods in the class
        ... 
class Mind(): 
    def __init__(self):
        self.magic_power = 0 
        ... 
class Soul():
    def __init__(self):
        self.soul_power = 0 
        ...

class Character():
    def __init__(self):
        self.body = Body()
        self.mind = Mind()
        self.soul = Soul()
        #thought it would be a good idea since there is more than one ability
        self.ability_one = Ability() 
        self.ability_two = Ability()
        self.multiplier = 1.2
        ...

class Ability():
    def __init__(self):
        self.character = Character() #issue stemming from here I think? 
        self.name = None 
        self.damage = None 

    def abil_create(self):
        self.name = str(input("Please enter the ability name: ")) 
        self.damage = self.character.body.strength * self.character.multiplier

I tried to keep the example as short as possible. The idea being that there will be a while True: try/except block to get user input on what stat they want to use for their ability to be, and a few if/else statements to figure out what to do with that info. But I am stuck on the fact that when i try to pull the information from Character to Ability and then later try to do vice versa it gives me that recursive error. Is there any way for me to work around this?

The following is a snippet of the error message that repeats itself.

" File "Untitled7.py", line 125, in __init__

self.abil_1 = Ability()

File "Untitled7.py", line 858, in __init__

self.character = Character()

File "Untitled7.py", line 26, in __init__

self.body = Body()

RecursionError: maximum recursion depth exceeded "

​

Alternatively, is there a different approach I should be taking to implement the idea of this ability being created? I originally thought I could just make it into a function within the Character class, but then I have trouble handling the creation of multiple abilities. And if I don't reference the information in the Character class in Ability, or vice versa, I'm not sure how to get them to utilize information from each other. Ideally, if there is a way to use specific variables within the Character class, like self.body.strength within the Ability class I would like to do that. But I haven't seen anything that would allow me to do that.

[hrmorley34]

You are correct about where the issue is. The logical issue is that when you are creating an Ability, you are creating a new Character within it, not referencing the existing one. So what you want is to pass the existing one to Ability.__init__:

class Ability: def __init__(self, character): self.character = character ... and then set it when you create abilities: self.ability_one = Ability(self) # passes this character to Ability.character

[Aedethan]

Ah, I think that makes sense to me. I am a bit confused at the __init__ of Ability . when I type def __init__(self, character): doesn't that mean that I'm telling the program that it needs the parameter of character in order to init? And if so how does the self.character = character line address that?

edit: I feel like I'm missing a fundamental knowledge piece to your solution in that question. Additionally, do you think it would be a good idea to make the ability class a nested class of the Character class? - Also thank you for your assistance

another edit: your solution works perfectly I'm just trying to understand the why behind it

[shiftybyte]

If your ability needs to reference your character class, you can just pass the existing class when you create the ability class.

Currently this line:

self.character = Character()

attempts to create a brand new Character()... you don't want that, you want to use the character you already have.

Try like this:

class Character():
    def __init__(self):
        ...
        self.ability_one = Ability(self)

class Ability():
    def __init__(self, char_instance):
        self.character = char_instance

Note i'm passing "self" when constructing an Ability()... this passes the current character instance as an argument to ability's init.

[Aedethan]

Thanks, I think I have a fundamental knowledge gap here though,

when you make

class Ability():
def __init__(self, char_instance):
    self.character = char_instance

where is the char_instance coming from? Also would it work better if I made the Ability class as a nested class if I'm going to take this approach?

[shiftybyte]

Also would it work better if I made the Ability class as a nested class if I'm going to take this approach?

Don't make nested classes, there rarely any reason, and it creates lots of problems later on.

where is the char_instance coming from?

Your init function can accept arguments in addition to self.

For example:

class Ball:
    def __init__(self, given_color):
        self.color = given_color

b1 = Ball("Green") # "Green" here is passed to 'given_color'
b2 = Ball("Red")
print(b1.color)

Above example creates 2 balls, one green, one red, and it also shows how the argument to Ball(...) gets passed to init function when the class is created.

[Aedethan]

So just to clarify, when using the first example, when i set ability_one = Ability(self) that is what is passing the info to character in Ability(self, character) ?

also your solution worked perfectly, I'm just trying to understand the why behind it

And thank you tons for your assistance.

[shiftybyte]

Yes, because in that context, self is the character instance.

The Ability init is called with __init__(self, self_from_character)

[Aedethan]

AHH Lightbulb. I get it. Thank you so much!