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Comment by ndr | Hacker News Reader

Using the id to prove it's reusing the same instance is a poor proxy, eg:

    >>> id([1,2,3]) == id([4,5,6])
    True
    >>> id([1,2,3]), id([4,5,6])
    (140720308985224, 140720308985224)

It's clearly not the same instance, even though it's at the same address.

Not in this case though, but I'm not sure why the author uses a black-box model to explain it rather than looking at the source, `iadd` uses `extend`: https://github.com/python/cpython/blob/main/Objects/listobje...

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You need to keep the objects alive obviously, then it works exactly as expected.

  >>> a = [1,2,3]
  >>> b = [4,5,6]
  >>> id(a), id(b)
  (140659402612872, 140659403098568)

Not to be rude or anything, but if the target audience needs basic semantics explained to them, I don't know they would benefit from an in-depth explanation.

But if if the author needs basic semantics explained to them, I don't know that the audience would benefit from reading it.

And why wouldn't an explanation help the audience learn?

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