Float/int is data type, but also a class ?

Thanks for clarifying Kenneth Love, looking forward to the advanced OO course.

1, So CLASS can never be called as TYPE, correct ?

• Str in meaning of Class, means that Str has some lower level structure elements under it's name. Str as class, is a general name for group of other functions, which are methods de facto.

2, But TYPE can be called as CLASS, correct ?

• Str is string type. it's type of value in python. it's an category of vaues.
• But Str, can be also Class. For example: str.rjust().

Thanks for reply Kenneth

There's really no such thing as "type" in Python. Or, rather, "type" isn't something distinct. A dictionary is a variable of the dict type and it's also an instance of the dict class. If I make my own class, all instances of it could be said to be of type MyClass or they'd, obviously, be an instance of MyClass.

Everything is an object, even types :)

EDIT:

If you're talking about using the type() function...don't use it. It's much better to use isinstance() because that'll traverse the inheritance tree.

1. Values have a type, yes, but those types are, ultimately, classes. We don't have any sort of untouchable type concept in Python.
2. Everything is an object and functions can accept and return objects, yes. I'm not 100% sure what you're asking here, actually.

"I'm not 100% sure what you're asking here, actually."

I will clarify. Imagine you are coding stuff in pc and someone is sitting near you. He checks monitor and start asking. What is that, what is this .... ?

On everything (every part of code) which he points out on monitor, can be called as Object ? Or when you still don't know, I'll ask: What is not an Object in code ?

Thank you

Ah, OK, I think I understand better now.

Under the hood, yes, they're all objects. But just like every car, van, truck, semi, etc is an automobile, if you were walking through a car dealership, asking what this one or that one was, you wouldn't accept being told "it's an automobile" about every single one.

So, yes, they're all objects, but you'll have a much better time working with them and talking about them to other developers by calling them lists or dicts or strings or MyClass or whatever they actually are.

Is Object just box or address in memory, storing a value ?

"Object" is a programming construct. Every variable (or instance, even if it doesn't have a name), just points to a spot in memory. That spot holds a string or a number or a pointer to some other variable or whatever that item is.

Now you defined what's happening under the hood when I assign a value to a variable. That memory thing.

But still don't know definition of Object. Please try again. It's important for me.

It depends on usage. If I have a variable that I've never seen before and I'm having to do some sort of investigative work on it, sure, I'll use type() to find out what kind of variable it is. In all my years of Python, this has never happened.

If, though, as is pretty common, I want to trigger something to happen based on the kind of variable something is, I'll use isinstance(). This doesn't happen a lot because it's a bit more proscriptive than Python wants to be, but it does come up from time to time.