`range()` doc doesn't note it's an immutable sequence

[NK5W]

Bug report

Bug description:

range():

• does not link to Iterators.

So, if we want to implement a custom class that

• is the same as range; or
• is lazy,

we will find it difficult.

CPython versions tested on:

3.15

Operating systems tested on:

No response

Linked PRs

• gh-138178: Doc: Clarify that range is an immutable sequence #138184

[skirpichev]

Could you please elaborate your proposal? It's not clear what you find difficult.

lacks a pilcrow

That's common with other cases of callables with multiple signatures, e.g. https://docs.python.org/3/library/functions.html#func-str

[StanFromIreland]

lacks a pilcrow

This is a duplicate of #137099, I will edit your issue to leave only the other topic.

[StanFromIreland]

Removing pending as it seems the linked PR has support.

[mpkocher]

In [1]: r = range(1, 3)

In [2]: next(r)
---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
Cell In[2], line 1
----> 1 next(r)

TypeError: 'range' object is not an iterator

In [3]: it = iter(r)

In [4]: next(it)
Out[4]: 1

Range is a bit of an odd duck.

https://treyhunner.com/2018/02/python-range-is-not-an-iterator/

[skirpichev]

Range is a bit of an odd duck.

Not at all. Documentation correctly describes it as a sequence type. Nothing to be fixed. I believe, this can be closed as a duplicate.

And you are right, it's not an iterator:

>>> r = range(123)
>>> isinstance(r, collections.abc.Iterable)
True
>>> isinstance(r, collections.abc.Iterator)
False
>>> isinstance(r, collections.abc.Sequence)
True

[StanFromIreland]

Oops I copied the PR title!