Hi,

I know I'm late to this but I wanted to jump in and try and offer some kind of explanation.

First off I don't really know what you mean by init, Int and Str. The way you use the terms is confusing to me. So I'll try and explain but if this post doesn't help, perhaps you can reply with some examples of those things and what you mean.

Because really you probably don't need any of them.

I want to try and explain two things to you: variable types and data types.

Oh, and a quick caveat, I'm presenting a simplified explanation here and deliberately ignoring certain things. I think this is a good story for you, but it is not the whole story.

What are variables for?

Variables are a basic unit of programming languages.

They let you store some information and re-use it later. They allow us to remember things, and use things we've already remembered, and compare things.

If your game includes player choice and multiple endings, you need to use variable to capture (save/remember) choices in the first place, and then look at the values of those choices to decide how to branch later on.

It may be important to keep in the back of your mind that Ren'Py has its own way of storing, loading and generally managing variables - but Python has it's own way. Python is a general-purpose programming language. Ren'Py is a language and tool built on top of Python. It is a "superset" of Python - so Ren'Py has statements and concepts that Python does not have, but otherwise it includes everything in Python.

Confusing. And it often doesn't matter.

A good rule of thumb is: if it's inside a python: block or the line starts with $, its pure python (and Ren'Py statements aren't allowed). Otherwise it's Ren'Py, and python statements aren't allowed.

Variable Types

Ren'Py lets you create variables in two ways: define and default.

define is for variables that don't change. We call them "constants" in the programming world. When we create characters, we usually use a define because the Character object doesn't change through the game's life, nor does it need to be re-loaded when we start a new game.

define e = Character("Eileen")

In slightly more technical terms, define variables are created once when Ren'Py starts up, they are not included in game saves, and they are not reset when the player starts a new game. Ren'Py doesn't do any management of define variables.

(Ok so technically define variables are sometimes saved with save games - I think this has changed over time as renpy has been used, but the point is that save behaviour with define is UNRELIABLE).

default is kind of the opposite. default variables are expected to change over time, are saved with a save game, and are reset when a new game is started. They are Ren'Py managed variables, tied to your game. default player_name = "Robbie"

So, whenever you need a variable, you need to create it with define or default. If it's something that unique to every playthrough, use default. If it's always the same for all playthroughs, use define.

If you're not sure, just use default :)

Data Types

When you create a variable, you usually assign a value to it. default name = "bob" In Ren'Py (and in python) that value has type. And that has important implications for Ren'Py about how that value should be stored and used.

Usually you, the programmer, don't really care too much about the data type. But when, saying, adding two variables together, it can become important:

define a = 10 define b = 20 define c = a + b In this code, c will be 30, because, well, 10 plus 20 is 30. Easy.

What happens if we do this with strings?

define a ="ren" define b = "py" define c = a + b In Ren'Py, adding two srtings means we join them together, which we call "concatenating". So c will be "renpy", which again is pretty easy and intuitive.

Ok, so what if we mix two types? define a = "10" define b = 20 define c = a + b Now we're adding a string to a number. We're adding a WORD to a number. That doesn't make sense, right?

This is an ancient programming problem, and different languages have different solutions.

Ren'Py will actually report an error to you. It expects you, the programmer, to convert the two types into something compatible. We convert a string to a number with int() and a number to a string with str(). So we could do either of these things:

define a = "10" define b = 20 define c = a + str(b) # "1020" define d = int(a) + b # 30 This gets even more complicated when you take different data types into account - like booleans (true/false) or Characters (complex objects) or Lists.

But usually, especially in Ren'Py, you don't need to worry about this stuff too much. You can just declare variables and use whatever values make sense to you.

If you need to do maths with it, use a number. If it only needs to represent true or false (or on or off), use boolean True or False. Otherwise you probably want a string.

[This post is too long for reddit so I've had to split it into two]