subprocess.Popen doesn't properly escape < or > for windows batch files

Bug report

Bug description:

subprocess.Popen doesn't properly escape < or > for windows batch files

example.bat

echo %*

example.py

import subprocess
from pathlib import Path

batch_file = Path().cwd() / 'example.bat'
subprocess.Popen([batch_file, 'arg1', 'arg2<99'])

Error

The system cannot find the file specified

Adding a space causes it to be correctly escaped:

subprocess.Popen([batch_file, 'arg1', 'arg2 <99'])

CPython versions tested on:

3.13

Operating systems tested on:

Windows

Linked PRs

• gh-134544

从 example.py 中报告的 subprocess.Popen 调用开始，使用参数 arg2<99 通过 example.bat 在 Windows 上重现它，然后将其与包含空格的参数进行比较。检查链接的 PR gh-134544 以了解当前工作状态；无空格的情况能够正确转义并且回归得到覆盖即表示完成。