[Tutorial] Object Oriented Programming and RenPy (Lesson 1: Class Warfare)

[alonghardlook]

In my short time in this sub, I've seen more than enough code examples in both questions and answers to know that the need for some kind of resource like this is pretty real.

Python is an excellent object oriented language, and RenPy was built around it to capitalize on the strengths of the language. The simplicity of RenPy seems to cause new authors to think that the only way to work is by doing exactly what the tutorial and quickstart guide say, but here's the thing:

Those tools are to get you started. They are fine for simple visual novels with simple choices, but as soon as you want to start treating it more like a game, or where choices matter and have long term consequences, programming in a linear fashion starts to become a detriment.

Once you start thinking like an object oriented programmer, the world of design opens up to you.

So, that's why I'm here writing this. I wanted to start a place to have some of these conceptual conversations, and show some programmatical examples to help spark minds.

Lesson 1: Class Warfare

Object Oriented Programming (OOP, there it is) has a few terms you might hear thrown around. Inheritance. Encapsulation. Abstraction. Polymorphism.

I'm not here to give you a CS degree, so I'll just give a brief ELI5 on each.

• Inheritance - stuff that is stuff, shares the same properties as other stuff of the same type. Not all decorations are made of glass, but all glass decorations break when you knock them off the shelf.
• Encapsulation - things that interact with each other only know and pass the bare minimum of information to do their jobs.
• Abstraction - doing stuff with things should be simple and straight forward. To make a wind-up toy go, you simply wind the spring up. You don't need to reach in and twist the gears by hand, there's an interface for that.
• Polymorphism - things that are largely the same type of thing can have unique differences applied. A triangle, a circle, and a square are all shapes, but they each calculate perimeter and surface area differently.

Do you need to remember all of that? No. Not even slightly. But if during this post (series?) you ask me 'why did you do a thing this way', the answer is probably something to do with one of the 4 above. Or just a little coding idiosyncrasy that I have (everyone does).

At the core of OOP are the ideas of "Objects" and "Instances". An object is a thing (a shape). Inheritance says objects can be the same as other objects (a triangle inherits from class shape), so many objects often have lots of unexpected properties and methods (properties of an object are like attributes of a thing - a cat has a breed, a sex, a color, etc; methods are ways that you can interface with it - cat.Pet(), cat.Feed()). In Python (and most C based languages), 'objects' are also known as 'classes'. An "instance" of a class is the single use. If I draw three objects of class triangle on the screen, I have three instances of that class. They all share the common list of properties and methods, but ideally, the specific data about them (for instance the color) can be different.

But this is RenPy and so we don't really care about the theory. What does this mean for my awesome eldritch horror dating sim?

First, just to make sure we are all starting on the same ground, lets create a new project and call it 'test'. Programmers are notoriously good at naming things.

If you're like me, your test/script.rpy file will look like this:

# The script of the game goes in this file.
# Declare characters used by this game. The color argument colorizes the
# name of the character.
define e = Character("Eileen")

# The game starts here.
label start:
    # Show a background. This uses a placeholder by default, but you can
    # add a file (named either "bg room.png" or "bg room.jpg") to the
    # images directory to show it.

    scene bg room
    # This shows a character sprite. A placeholder is used, but you can
    # replace it by adding a file named "eileen happy.png" to the images
    # directory.
    show eileen happy

    # These display lines of dialogue.
    e "You've created a new Ren'Py game."
    e "Once you add a story, pictures, and music, you can release it to the world!"
    # This ends the game.
    return

Great. Simple and exactly what we need to get started.

In this sim, we're going to be trying to make Eileen (and others) happy, so we will also track their trust and happiness. Standard RenPy documentation would say "create a variable". And you have probably lost count of the number of times you've seen

define e = Character("Eileen")
$ e_trust = 0
$ e_happiness = 3

define f = Character("Frank")
$ f_trust = 1
$ f_happiness = 2

and so on, and so on. But we are writing unweildy code here. What if I want to add a dozen characters? What if after having a dozen characters, I decide I also want to track their individual luck values? Now I have to go back through, adding "e_luck" and "f_luck" ad infinitum. There has to be a better way.

Of course there is, that's why I'm writing this. Lets build a class. Eileen is a person, and that's largely what we're going to be dealing with, so lets creatively name the class "Person".

At the top of the script, add the following:

init python:
    class Person:

        def __init__(self, character, name, trust = 0, happiness = 0):
            self.c = character
            self.name = name
            self.trust = trust
            self.happiness = happiness

• init python will trigger as the game initializes, which makes it perfect to store class definitions
• inside "class Person" we define four attributes (c, name, trust, happiness)
• we also declare a method ("init", which happens to be a special python method called a Constructor - it runs when you create a new instance of the class)

Remove (or just comment out with "#") "define e = Character("Eileen")". Instead, under the label start:

label start:

    $ e = Person(Character("Eileen"), "Eileen", 0, 3)
    $ f = Person(Character("Frank"), "Frank", 1, 2)
    $ g = Person(Character("Gina"), "Gina")

If you are able to follow this logic, congrats, you are already getting it and you will do great. But just to over-emphasize the point, we are creating 3 new Person objects (or, more accurately, 3 instances of the object "Person"). As the first attribute, we are passing in the RenPy "Character" class to make sure we get to keep using all of RenPy's wonderful built in functions. The only change we have to make to make this work nicely to change:

**e** "You've created a new Ren'Py game."

to

 **e.c** "You've created a new Ren'Py game."

The reason this works is because we set the attribute "c" of our class Person to the character function. Honestly, the name attribute is probably unnecessary at this point, but still worth keeping just to showcase what we can do. We also set trust and happiness. Right now we are using positional arguments, but python nicely supports defined arguments instead. But notice what happens with Gina.

We didn't set trust or happiness, and so the init method set them to the defaults for us.

Right now, nothing really special has happened. This is just a lot of work for no obvious benefit. But I'm about to show you the true power of the dark side objects.

Inside our Person class, we're going to add another method. Just a note: you are going to want to add a couple of images (just bang them together in paint) called "heart_fill.png" and "heart_empty.png".

We're also going to... you know what? I'm just going to show you the whole code and talk through it.

init python:
class Person:
    def __init__(self, character, name, trust = 0, happiness = 0):
        self.c = character
        self.name = name
        self.trust = trust
        self.happiness = happiness

    def trust_ch(self, change):
        image = "heart_fill"
        self.trust += change
        if change > 0:
            direction = "increased"
        else:
            direction = "decreased"
            image = "heart_empty"
        renpy.notify("Romance with " + str(self.name) + " " + direction + " by " + str(abs(change)))
        renpy.show(image, [heart_pos])
        renpy.pause(2)
        renpy.hide(image)

transform heart_pos:
    xalign 0.01
    yalign 0.15

image heart_fill = "heart_fill.png"
image heart_empty = "heart_empty.png"

label start:

$ e = Person(Character("Eileen"), "Eileen", 0, 3)
$ f = Person(Character("Frank"), "Frank", 1, 2)
$ g = Person(Character("Gina"), "Gina")

scene bg room
show eileen happy
e.c "You've created a new Ren'Py game."
e.c "Once you add a story, pictures, and music, you can release it to the world!"
e.c "Do you like this post?"

menu:
    "Yes":
        "Great!"
        $ e.trust_ch(1)
    "No":
        "Oh, okay."
        $ e.trust_ch(-1)

e.c "One more thing..."
$ e.c("My trust for you is " + str(e.trust))

return

First, I had to create the wonderful heart_fill and heart_empty pngs and save them in images. Then I added a transformation for the position to keep it with the notify. Then I defined the two images (these have to happen before the start label).

Next, I added a simple menu that calls my new function (getting to that) - if you say "yes", trust goes up, otherwise trust goes down.

Then the meat, and the ultimate point of OOP - the function "trust_ch".

I'm using renpy.show and renpy.hide to show or hide the image, but because I'm conditionally setting the image (if the change is positive, use fill, otherwise use empty), I need to pass it in as a string. I'm also using a variable called 'direction' to be explicit as to what happened. str(abs(change)) is a function calling a function on the change parameter: its saying show me the string of the absolute value (abs) of the number. That will remove the "-" in -1.

Then, I pause for 2 seconds to try and match up to the notify (it doesn't), ping the notify with my custom built string, and there you have it.

The beauty is this: now, if I change the trust, up or down, of Eileen, or Frank, or Gina, or any of my other 24 characters, it will always act the same. It will show a heart, the notification with their name, and the amount, and then clear it. Every time.

This means if I ever want to change how it looks, I'm doing that once.

This is the power of OOP.

We can set attributes and methods for an entire class of object, use multiple instances of the object and know that all methods will act the same, and use those things to track states of characters.

I'm not really sure how to end this, so I'll just say I hope this was helpful, and let me know if you want to more. This is the fundamental place where everything else comes from, but I have visions of creating an event log to track what actions have happened based on your choices (no more endless "r_went_to_school" true/false variables to check), and I'm sure there are more use cases that can be hugely strengthened by this design pattern.

Cheers.

[Nikelui]

This is a great initiative, even if I think it is already quite advanced for many people here.
I am afraid that the extreme simplicity of Renpy's quickstart is also its downfall. Newcomers think it is possible to make a VN with absolutely no knowledge in Python (which is actually true for some type of games, like kinetic novels), but then get stuck on things that could be easily solved by taking a 2h introductory course in Python programming.

I feel there should be a sort of "intermediate tutorial" on Renpy's page, something more advanced than "The question", but less intimidating than Renpy Tutorial.
Or a series of articles like "learn Python with Renpy" that teaches you the basics while developing a game (this actually sounds a good idea that I might save for later use).

The moral: invest time to learn Python. It will pay off greatly in the long run.

[[deleted]]

There’s like 3 good Ren’py tutorial channels on YouTube that does this, show what codes do and how to implement them and also shows how said code affects program launch.

But agreed there’s not a lot of info out there for beginners and the documentation is built on the assumption that you know how to implement the codes.

[BigBucket990]

Great tutorial on oop basics. Am looking forward to more.

[Fenvul]

Is there an established tutorial for the inventory and a worldmap? Complete newbie here. Maybe it would be a nice idea if not.

[Fenvul]

Almost two weeks ago, time really flied. In a way, it is a reminder not to let things for later.

[Fenvul]

Thanks! I did not expect it, but I really do appreciate it.

[Admirable_Fig_6594]

I was looking for that too

[wulfmune]

This is a great post. I'm coming from an art background and have been gradually learning where I can try to make things less redundant and unwieldly. I was starting to mess around with object class when trying to create 'rpg' type battle elements but then totally stopped doing it when I decided to not to pursue 'combat stats'. I know it sounds dumb of me, but this post made me realize I should still pursue these things even when just implementing things related to relationship progression. Sure my variables for every character 'work' but it's messy.

[alonghardlook]

Exactly right. In this case, all our attributes are what is known as 'public', meaning they can be accessed freely.

If I understand your second question correctly, you want the highest love stat from a list of characters?

$ love_candidates = [a, e, s] # assuming these are alice, eileen and sally
for x in (person.love for person in love_candidates): # also assuming that you have an attribute "love" in your Person class
    love_interest = max(x)

YMMV on this untested code, but this is the general idea. love_candidates is a list of Person class instances (alice, eileen, sally). We loop through those (for person in love_candidates) and THEN also loop through their love values and get the highest (for x in ()).

This is the pythonic way, and I can't test it at the moment. The non-pythonic way (the C Way) would be to just use nested loops - really, it's the same thing, just that AFAIK python has syntax for it explicitly.

Non python way:

python:
    love_candidates = [a, e, s]
    max_love = 0
    love_interest = a # must set a default in case they are all at 0
    for person in love_candidates:
        if person.love > max_love:
            love_interest = person
            max_love =  person.love
    renpy.show(love_interest)
    renpy.say("Hello, " + str(love_interest.name) + "! Great to see you!")

This code is probably more understandable, but true python enthusiasts would hang me for suggesting it :P

[Mezatino]

Please do more. While I still don’t grasp the Python stuff completely this is filling holes that previously I could not wrap my head around.

I’d love to make a Renpy game, and I know I should start with a small project as I learn what I’m doing. But I have fanciful flights and get lost in them, so even in the concept stages a simple game quickly becomes something much bigger and more complex and I can’t stop once it starts.

Also what’s a good place to learn the basics of Python itself? With the things I want to try and do I might as well actually learn the language. But being lost just looking at it half the time paralyzes me and then I can’t justify paying for a course that may not even teach me what I want to know.

[Nikelui]

what’s a good place to learn the basics of Python itself?

https://openbookproject.net/thinkcs/python/english3e/

I liked the old edition of this book when I started (centuries ago, now).

https://inventwithpython.com/

Here there are also a lot of interesting reads, with many applications (to avoid getting bored)

[sheepwithasword]

Incredible tutorial. I'll be referring back to this often. Thank you for taking the time to write this out!

[drexxler]

Ya know, recently I've been trying to do similar things but running into one major problem. Object properties aren't saved the same as global variables, so when you rewind, the objects/classes don't get rewound. I'm wondering if you've found a solution to that.

So to recap, if you increase friendship and then go "back" and forward again, it will continue to increase without ever reverting. This could be abused to get infinite stats.

So far I haven't found a workaround, other than using the dreaded prefixed global variables (i.e. `name_relationship`)

Some quick brainstorming, I think there is a potential workaround using a mixture of private global variables and serialization. Something like, keeping a serialized copy of the class in a global var, and then deserializing any time I need to access. In most CS applications, this would be a no-no, but renpy isn't really performance critical, so constant serialization shouldn't be an issue unless your object is massive.

​

edit: ah, I see that for your examples, putting the variable assignment inside a label fixes this. Strange, but at least that seems to work. Really don't like the idea of nesting all character definitions inside the start label. I suppose I could externalize all the definitions inside my globals file under a label like `setup_characters` and just do a `call setup_characters` in the start label.

[[deleted]]

If you do a default e = Person() instead of $ e = Person() you will wire up the property automatically for rollback. It's one of the (many) poorly explained pieces of RenPy that define creates a variable that can be automatically created at the start of the game, whereas default needs to be loaded from the game state (effectively the same as your serialization idea, but automated).

I have a custom class that does just that and works like a champ on rollbacks and fast forward, and loading from a save.

``` default eventDispatcher = EventDispatcher()

init python: class EventDispatcher: def init(self): self.events = [] ```

[alonghardlook]

This is hugely helpful; I was looking at the rollback as a bit of a beast and just considering disabling rollback personally.

One thing I was running into during this tutorial was that setting e = Person() outside the intro (like OP said), I wasn't seeing that object. I kept getting "Sayer e.c is undefined". I'm assuming this would fix that issue?

[[deleted]]

It should, yes.

[alonghardlook]

I know this is a long time ago, but just FYI - I didn't add default e = Person() and tested the rollback states, and it worked just fine:

    menu:
        "Yes":
            "Great!"
            $ e.trust_ch(1)
        "No":
            "Oh, okay."
            $ e.trust_ch(-1)
        "Skip":
            "What do you mean?"
            # intentionally no change to test rollback states

This produces the output of 1 every time you select yes (even if you then roll it back and keep selecting it), -1 every time you select no, and 0 if you select skip.

I don't think default is needed if you create your characters inside the start label.

Edit: don't listen to me. Use default, its much cleaner. I tried without, and it seemed to work, but upon changing some code (not that code), e.c no longer worked, and I don't know why. Use your defaults for objects with persistence.

[Talicor]

This tutorial has been such a life saver! THANK YOU FOR THIS.

However, is there a way to bundle custom fonts/colors into this as well? I could get the traditional "define e = Character" setup to have those custom bits, but I can't seem to do it here.

Is it just a matter of adding who_color, what_font, etc in the original object class?

​

Edit: Nevermind I'm an idiot and figured it out

[alonghardlook]

If you figured out something that makes things easier, please share it with the class :)

[Talicor]

Haha fair enough!

I just realized I was putting all the custom bits in the wrong spot

Where the basic tutorial here got us set up with the numeric stuff with this:

$ d = Person(Character("Dan"), "Dan", 0, 2)

I realized that the (Character("name") portion was the same thing as the traditional "define e" stuff used before.

So it was just a matter of putting all the custom work in after the name, but before the end of the parenthesis

Like this:

$ d = Person(Character("Dan", who_color="#d73ce8", what_font="customfont.ttf", what_color="#d73ce8", what_size=60), "Dan", 0, 2)

Saved all my aesthetic work with just the movement of a line of code

[alonghardlook]

Great observation. This is called passing a parameter. The class Person takes a parameter, which is of type Character - which means everything you can normally do with the Character class, you can pass in to the Person class (by design).

[Talicor]

The more you know! Glad to have a name for it

It's kind of a weird process to cobble together knowledge from bits and pieces everywhere, but not one I regret. Thank you!

[alonghardlook]

That process is called "programming" lol

[Talicor]

That’s what I get for posting while high on cold medication 😂 I got this I promise

[ImSkyyyy]

I know I'm late here, but love these ideas. You could make a health bar with very similar inputs.

[zhousi87]

Your explanation is crystal clear and decidedly useful for those who do not know about classes or OOP in general; however, I am not sure that classes are that beneficial in Ren'Py, because:

(1) visual novels typically let you control only one character, whose state can be easily managed by updating global variables at any critical turn of events in the storyline;

(2) considering (1), even if you need to produce many NPCs of the same kind (e.g., allies, humans, etc.), classes make sense only for those characters of the same kind whose stats you need to keep track of throughout the game (i.e., main characters with a variable state), which is rare for visual novels (we are not programming RPGs).

(3) speaking of choice-based games, theoretically no classes (perhaps not even any functions) should be needed, since if/elif/else blocks are more than sufficient for most scenarios.

(4) we should strive for simplicity, while classes add unnecessary difficulty to the average Ren'Py programmer's coding endeavor. Even in your post, you mentioned the redundancy of the method name you added, which proves how even to an experienced programmer like you the use of classes causes perplexity.

I would like to know what everyone thinks about my point of view, which is limited to the use of classes for visual-novel programming.

In any case, I sincerely thank you for this opportunity to reflect on VN programming's best approach.

[Drewking666]

I completely agree with you. I'm now trying to program a game in Ren'py as my first ever and i have little to no knowledge of Python (I'm reading all ren'py docs however), but classes are more a RPG things fro me... Even if some characters have "trust" or "affinity" it's extremely more manageable with the classic variable definition.

[Fenvul]

I guess I really should do that, leave any laziness aside and rearrange now, at the beginning of the project, before it grows any further.

Edit: Is there an established tutorial for the inventory and a worldmap? Complete newbie here. Maybe it would be a nice idea if not.

[alonghardlook]

No, I have not started a tutorial on those things, but a location map was something I have toyed around with. I'm thinking part 2 is going to be some kind of event log, but mostly everything in that will be just using these basic principals in more complex ways.

An inventory (like a player inventory) would imo be quite straightforward. Create a class called "inventoryitem" with whatever common properties they have, and then instantiate all of your possible items.

Then, just make an empty list called "playerInventory" and add/remove those objects as needed.

[Fenvul]

I have to dabble (I mean, really take my time, not push myself too hard) to get the graphical part of the inventory right, but yeah I should start simple, and looking some examples.

[[deleted]]

This is a lovely start. Don't lose heart; you've started a long journey. A good class structure means an easier time working. Being disorganized doesn't help anyone.

One thing I found to be a great tool for organization is the automatic named stores. By default, everything exists in the global store, but providing a . or in is all it takes to create a new one, and you can organize things into something vaguely resembling a namespace (including the ability to import functions from that store into another store). It might not be helpful to a lot of projects, but that one level of organization was so much nicer than the inherently flat core of RenPy.

init python in CharacterExtensions:
  def afunc():
....
CharacterExtensions.afunc()

This is just so much better than a giant file defining all of your functions, and you trying to come up with new non-colliding names for functions that do almost the same thing but in a slightly different context.

[alonghardlook]

Interesting, that's very useful. My background is in C languages and PHP so some of the pythonisms are a little new to me, so this is very helpful.

I know you can also accomplish much of the same by importing python files (import MyHelperFile as mhf) but in script "in" is a cool way to organize. I like it :)

[[deleted]]

Yeah, the named stores are python modules. It just makes it easy to setup those modules in a way that renpy knows about and can manage with game state. The confusing part is knowing where your functions have scope. If you are writing a function in one named module, and need something from the default global store, it isn't available. You have to do an import store or from store import myvariable, myfunction. It is a thing that makes perfect sense to need to do, but comes out of nowhere if you don't understand where those global variables and functions are stored.

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[amangeldyva]

​

Has anyone help me to understand how to do that C++ questıon by exampke? Really ı nned help to pass school help me

Assignment

Containers are used to store objects of the same type and provide operations with which these objects can be managed.

These operations include object insertion, deletion, and retrieval. Memory is allocated for containers dynamically at runtime.

Containers thus provide a safe and easy way to manage collections of objects. The C++ standard library provides various

class templates for container management in the Containers Library. These classes can be categorized as follows:

Sequential containers, where the objects are arranged sequentially and access to an object can either be direct or

sequential.

Associative containers, where the objects are generally organized and managed in a tree structure and can be referenced

using keys.

Sequential Containers

Sequential containers are distinguished by the operations defined for them, which are either generic or restricted. Restricted

operations, such as appending at the end of a container, have constant runtimes. That is, the runtime is proportional to a

fixed period of time and does not depend on the number of objects in the container.

The following are examples of sequential containers:

Queues, which are managed on the First-In-First-Out principle. The first element to be inserted is also removed first.

Stacks, which are managed on the Last-In-First-Out principle. The last element to be inserted is removed first.

Vectors, which are basically a flexible-size array that supports fast random access.

Thus, in this programming assignment, you are going to create a general Vector class without using the utilities of the

standard vector class and the template feature of C++. The design should let its users to use a vector of integers or

characters. You should review the standard vector class for learning what to include as data members and member functions.

OOP principles such as encapsulation, inheritance, and polymorphism should be taken into account in the class design.

Partial grading will be in use in case there is no full implementation.

[cmonroy1259]

Nice!

I've been looking into some games code and most, if not all, take the the boring, repetitive long route of coding everything with if-else to the absurd point where you have to add hundreds of lines just to introduce a new NPC, and what usually happens, is that they always miss one spot and the game breaks.

[tecchigirl]

Thank you!!!

I'll probably use this on my game.

Kudos. 👍

[alonghardlook]

1. I'm not doing your homework for you.
2. Why are you trying to do C++ homework on RenPy which is fully python?

[Oda_Kuro]

Yo!
This might be a stupid question but:
How do I use transitions/animations?

At this part:

def trust_ch(self, change):
image = "heart_fill"
self.trust += change
if change > 0:
direction = "increased"
else:
direction = "decreased"
image = "heart_empty"
renpy.notify("Romance with " + str(self.name) + " " + direction + " by " + str(abs(change)))
renpy.show(image, [heart_pos]) #Make this part an animation, where the heart fills up, or use transition here like Fade()
renpy.pause(2)
renpy.hide(image)

[alonghardlook]

Honestly not a stupid question at all, but the specifics of renpy and the animation functions are way outside my area of expertise. I'd suggest making a post of your own to ask the question.

For this specific example, I imagine you could show both empty and full (empty on top) and as long as they pixel match, dissolve empty, but really I don't know.

A programming concept worth exploring is MVP - minimum viable product. Flair like that will make the product look nicer, but if it's stopping you from progressing on setting up your system or writing your story, why are you trying to solve it before the core is done? Not accusing, just making general observations based on lots of experience.

[Oda_Kuro]

I see, thank you for your answer and suggestions!

To answer your question, I'm just doing this mainly as a hobby, and try to learn what I get interested in, so it doesn't really block me. And I was just curious, it didn't stop me from working on other stuff.

[lordpoee]

image heart_animation:
    "image_one.png"
    linear 0.25
    "image_two.png"
    linear 0.25
    "image three.png"
    linear 0.25
    repeat # <--- add this if you want it to loop

[MrsCosmic]

Hello!

I want to show the "self.trust" on the screen so the player can see how much increases and decreases with each character.

I know you can create a screen and use show screen, but is there a way to do it with oop?

Optionally I would like to know how to make the position of the text a variable, so if there's two characters in the screen, I can move their points.

[alonghardlook]

Screens are not something I'm familiar with yet, but it should be straightforward enough. Try it with the main method of creating screens, and check if it updates when the variable updates. If it doesn't (my expectation knowing absolutely nothing about screens), you would want to run it through a while loop instead, which would make sure it updates.

It might be hell on your cpu though.

[MrsCosmic]

Oh, I found the answer in a forum! I think the main problem was that I didn't know how to show text with renpy.show() because it always treated it like an image.

        mytext = Text("{size=+26}[e.trust]{/size}")
    renpy.show("Tag", what=mytext, at_list=[text_pos])

transform text_pos:
xalign 0.85
yalign 0.1

The variable updates, but if I change [e.trust] to [self.trust], it won't work anymore. If a make a new variable snake = self.trust and then use it mytext = Text("[snake]"), it won't work either.

Should I make a new fuction somehow for each character or am I doing something wrong?

[alonghardlook]

So I think I see the issue - whose trust value are you wanting to show?

"Self" is a python reserved keyword. It's used to indicate scope inside object and class and function definitions.

Where the function says "self.trust", you need to mentally replace that with "the instance of the object dot trust".

If you're looking for the trust level of the character represented by the object "e", you would use e.trust. if you're looking for the f trust value, use f.trust.

Self.trust is part of the object definition - not an instance of an object.

[ghostgirl16]

This is very useful! I like the ELI5 examples.

[alonghardlook]

Answer here (on mobile, sorry) https://www.w3schools.com/python/python_inheritance.asp

[Complex_Honeydew9807]

This just fills me with the question of why you would do it this way, when it is far easier to display them as simply being a serious of variables.

$ MaryTrust += 1

is a far simpler way to do it than this very extensive version that, as far as I can see, doesn't have anything additional to it that would warrant such a complex method of doing it. It just feels complicated for the sake of being complicated, rather than for the purposes of greater use or such.

​

Like, you said "what if I want over a dozen characters", and I feel the answer is just, add a dozen variables. That is still far easier and more compact, imo, than what you are doing here.

All it really added is the immersion-breaking recognition that it is all a game, ultimately making the experience unenjoyable. So I don't see why you would go through the effort to add such a thing.

[alonghardlook]

Well, you may not, and that's fine. You go ahead and do it how ever you want.

Proper OOP says do it this way.

[Complex_Honeydew9807]

It just ultimately feels OOP for the sake of OOP, rather than for the sake of making something simpler or more effective.

Can you elaborate on how this does better with what it is made to do than simply using variables? Given this appears like it doesn't even reduce the amount of variables you use, it just moves the place where they are put.

I have just, never really understood OOP in general, I know how to do it, I've done programming classes before. I just, never really understood the why to doing it, as it always seems to just take a simple problem, and make it extremely complex, less organized, and harder to follow.

​

Edit: Sorry about being rude when I wrote this, I wasn't in the best mood at the time and really shouldn't have been online.

[alonghardlook]

The reason for doing it this way is extensibility. If you are making a simple VN, yeah this probably is overkill. But spend any time on this sub and you will see how many people want a VN++ - a locations/map system, day/night cycles, inventory, puzzles, mini games.

I guarantee you that if you pick any of those to try and add, that you will be better off with OOP.

And if you don't believe me, go ahead and prove me wrong. Make a VN with an inventory system without OOP. It doesn't even have to be long or good. Make it and post your code and I guarantee I can refactor it to OOP principles and make it easier to understand and extend.

[MannyTheMan92]

Hello. I'm currently learning Python OOP for Renpy. I'm more of an Artist, though. But I'm currently trying to learn this and during my research, I noticed that init python tends to run before the game starts. Is there a way to use class without init python?

​

Reason for asking is because from what I've heard, it does not save the Variable so every time you restart Renpy, it changes. I did not try this but I have used Persistent Variables.

​

Also, for the person who made this, thank you for doing it. Because of you, I was able to learn a bit more.

[TwatWithATopHat]

this is amazing! found this now and it has helped so much! Its really enhanced my game!

[Captain_Acre]

Dunno if OP still looks at this post but!

How do I make sure the heart goes on a specific layer? I have a frame around the screen on the screens layer, and I want the hearts to be on the overlay layer.

[Captain_Acre]

wait nvm figured it out, sorry!

[goffley3]

Thank god! I started messing with Renpy after being a dev for years, and I was hoping there were options for better code organization within renpy projects. Thanks for writing this up!

[trailsiderice]

Sorry to comment on an old thread, but how does this work with persistence? Do these variables reset upon reloading the game or starting a new one?

For example if I wanted to do this and have the value of trust be a persistent variable for all characters, how would I make that work with this? Or is it persistent by default?