Python data structures and class

Question

If we have :

K = [3,4,5]
T = (3,4,5)

and we call these commands :

print(type(K))
print(type(T))

we have these prints :

<class 'list'>
<class 'tuple'>

I know that K is a list and T is a tuple, but I'm not sure whether K or T are also classes or not ? We have commands like K.append() and similar commands, this makes me unsure about the concept.

Everything in Python is an object, and everything has a type (their class). — Martijn Pieters, Oct 28 '16 at 18:08
`K` and `T` are not themselves classes. They are *instances*; one is an instance of the `list` class, the other of `tuple`. — Martijn Pieters, Oct 28 '16 at 18:09
Just because something has an _attribute_ (i.e. `foo.bar`) doesn't mean it is an instance of a class. Non-class objects can have attributes too. — John Gordon, Oct 28 '16 at 18:10
@MartijnPieters oh I think I got it. list and tuples are classes in python, but here K and T are instances of those classes. right? — Alireza Ghorbi, Oct 28 '16 at 18:13

score 0 · Answer 1 · edited May 23 '17 at 10:34

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K and T are instances of python's List and Tuple data types. Types generally have some associated attributes, just like classes. See more about data structures and implementation here.

These are not necessarily class objects, however. This SO post should clarify the difference between a data type and a class.

edited May 23 '17 at 10:34

Community

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answered Oct 28 '16 at 18:15

Sondering Narcissist

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score 0 · Answer 2 · answered Oct 28 '16 at 18:17

List and tuple are build-in classes in Python, that's why you can write list() to create a list and tuple() to create a tuple. You just creating an instance of the class list/tuple. You can also deckare a list by using "[" and "]" and a tuple by using "(" and ")", because these so called "operators" are standard syntax of Python.

Python data structures and class

2 Answers2