Calling unittest.assertDictEqual for medium-size dictionaries takes too long

Calling assertDictEqual(d1, d2) / takes forever, even for medium-size dictionaries. To reproduce:

from unittest import TestCase
from random import randint

    def test_assert_dict(self):
        r = 10000000
        num = 10000
        d1 = dict((randint(0, r), randint(0, r)) for _ in range(num))
        d2 = dict((randint(0, r), randint(0, r)) for _ in range(num))
        self.assertDictEqual(d1, d2)

Probably related to issue #63416.

Tested on Python 3.10, Windows 11

Linked PRs

• gh-126923

从提供的 Python 复现开始，检查 unittest.assertDictEqual，然后阅读 issue #63416 和链接的 PR gh-126923，了解现有背景。完成标准是：中等大小字典的比较不再耗时过长，并且已根据该复现检查行为。