Improve error message for Element.remove()

[serhiy-storchaka]

Feature or enhancement

Currently it imitates the error message for list.remove() and other collections: "Element.remove(x): element not found". But Element is not a general collection, so reasons for such error message are not applicable:

1. It can only contain other elements.
2. It may be useful to know what exact element was removed and from where. Their repr is limited, so it can be included in the error message.

Linked PRs

• gh-142306: Improve errors for Element.remove() #142308

[picnixz]

I think I changed this one because I wanted to keep the existing messages but I don't remember. However, if we include the repr of an element, wouldn't it be then an issue if the element is very large?

[serhiy-storchaka]

No, because the size of the repr of the element is limited (*), it does not depend on its size. This is the difference from general collections.

*) If you don't create elements with unreasonably long names.

[picnixz]

Oh then I guess it's fine!