ElementTree.iselement() returns true for the Element type

According to documentation, ElementTree.iselement() check if the argument is an element object.

But it returns true also for the Element type which has all attributes of an Element instance. The way how the Element class is defined in Python suggests that this may be intentional, but the intention was lost in the documentation.

There is also an example of dataclasses.is_dataclass() which returns true both for a dataclass type and for a dataclass instance.

So, there are two ways:

1. Fix the documentation to match the current behavior. All uses of iselement() (see #135640) should also check if the argument is a type is they need an element object.
2. Fix the implementation to check if the argument is a type. This may break the user code that uses it to check for the Element type (I don't know if it exists) but may fix bugs in the user code which expects that iselement() works as documented.

cc @scoder

Linked PRs

• gh-136482
• gh-136484

從 ElementTree.iselement() 的文件與實作開始，接著檢查相關的 PR gh-136482 和 gh-136484，以及 #135640 中參照的使用處。完成的標準是釐清應該變更文件所述的行為還是實作，並一致地更新相關行為或文件。