`ElementTree.parse` type hinted to return unusable generic types

Bug Report

Since upgrading to mypy 1.15+, using ElementTree has become increasingly difficult. Likely due to https://github.com/python/typeshed/pull/13349. I'm not sure if this extra strictness is expected or if I'm just holding it wrong.

One example is the ElementTree.parse function that now returns a generic ET.ElementTree[ET.Element[str]], which is no longer compatible with basic type signatures like ET.ElementTree, which is interpreted as ElementTree[Element[str] | None].

This adds many challenges that make it difficult to work with.

• The generic argument here is very difficult to understand what it means and is lacking documentation. From what i've been able to deduce it's possible that the root node is of a different Element type or that the root node is None. While perhaps a valid scenario, it adds a big uphill to learning and usability.
• If one were to use these generic types, typing out ET.ElementTree[ET.Element[str]] is a lot more verbose than ET.ElementTree, and i'm questioning if the strictness here is worth it.
• If one tries to type hint the code with these generics. Python throws errors that 'ElementTree.Element' is not subscriptable. One workaround i found for this is to surround the type hints with double-quotes.

To Reproduce

import xml.etree.ElementTree as ET

def process_document(doc: ET.ElementTree) -> None:
    pass

def process_document2(doc: ET.ElementTree[ET.Element[str]]) -> None:    # TypeError: type 'xml.etree.ElementTree.Element' is not subscriptable
    pass

process_document(ET.parse("foo.xml"))     # mypy error: Argument 1 to "process_document" has incompatible type "ElementTree[Element[str]]"; expected "ElementTree[Element[str] | None]"  [arg-type]
process_document2(ET.parse("foo.xml"))

Run with mypy --strict

Expected Behavior

ET.parse returns types assignable to ET.ElementTree

Actual Behavior

Mypy returns errror

# mypy error: Argument 1 to "process_document" has incompatible type "ElementTree[Element[str]]"; expected "ElementTree[Element[str] | None]"  [arg-type]

Workarounds

• Use ET.ElementTree().parse() function instead of ET.parse(), it returns the root-node as a type that can be assigned to ET.Element without any generic arguments.
  This is actually a pretty decent option, if this is considered to be the primary way of using ElementTree from now on, the documentation should reflect that, right now it's suggesting ET.parse()
• Type out the complete "ElementTree[Element[str] | None]" wrapped with double-quotes.

Your Environment

• Mypy version used:
• Mypy command-line flags:
• Mypy configuration options from mypy.ini (and other config files):
• Python version used:

首先阅读 typeshed PR 13349 以及 ElementTree.parse 的注解，然后将其与 ElementTree().parse() workaround 和 Python ElementTree 文档进行比较。完成的标准是明确预期的泛型行为和 ET.parse() 的预期可赋值性，并处理相关的 typing 或文档问题。