Description

NekoAsakura

opened on Feb 15, 2026

Issue body actions

Bug report

Bug description:

Element.__init__ has the same Python/C signature inconsistency as SubElement (gh-144270).

Python fallback:

cpython/Lib/xml/etree/ElementTree.py

Line 167 in 23c488d

def __init__(self, tag, attrib={}, **extra):

tag accepts keyword arguments: Element(tag="foo") works.

C accelerator:

cpython/Modules/_elementtree.c

Lines 419 to 420 in 23c488d

	if (!PyArg_ParseTuple(args, "O|O!:Element", &tag, &PyDict_Type, &attrib))
	return -1;

PyArg_ParseTuple only parses positional args, so tag is positional-only. Element(tag="foo") raises TypeError.

Proposed fix

-    def __init__(self, tag, attrib={}, **extra):
+    def __init__(self, tag, /, attrib={}, **extra):

Same pattern as the SubElement fix in gh-144270.

Reproduce

import sys, importlib
import xml.etree.ElementTree as ET

root = ET.Element("root")

try:
    ET.Element(tag="foo")
except TypeError:
    print("C rejects Element(tag=...)")

sys.modules['_elementtree'] = None
importlib.reload(ET)

e = ET.Element(tag="foo")
print(f"pure-python accepted it: {e.tag}") 

CPython versions tested on:

CPython main branch

Operating systems tested on:

Linux

Linked PRs

• gh-144846: make Element tag positional-only #144876

Activity

1. NekoAsakura

   added

   type-bugAn unexpected behavior, bug, or errorAn unexpected behavior, bug, or error

   on Feb 15, 2026
2. brianschubert

   added

   stdlibStandard Library Python modules in the Lib/ directoryStandard Library Python modules in the Lib/ directory

   topic-XML

   on Feb 15, 2026
3. brijkapadia commented on Feb 16, 2026

   

   brijkapadia

   on Feb 16, 2026

   Contributor

   More actions

   @NekoAsakura Do you want to create a PR or could I work on it?
4. NekoAsakura commented on Feb 16, 2026

   

   NekoAsakura

   on Feb 16, 2026

   MemberAuthor

   More actions

   Hi @bkap123 , cheers for the shout! I've already got the fix ready to go. I’ll whip a PR up now.

   Reacted by Brij Kapadia
5. NekoAsakura

   added 2 commits that reference this issue on Feb 16, 2026

   pythongh-144846: make Element tag positional-only

   e0895a4

   pythongh-144846: make Element tag positional-only

   aa2871b
6. NekoAsakura

   closed this as completedon Apr 1, 2026

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