argparse option argument with `nargs=argparse.REMAINDER` is misplaced in usage line

Bug report

When using an optional argument with nargs=argparse.REMAINDER, the argument appears within the list of optional arguments and before any positional arguments. I expected it to be placed last in usage line, which would better match the behavior since it consumes any following parameters. Not sure it is really bug...

The following scripts shows the issue:

#!/usr/bin/env python

import argparse

parser = argparse.ArgumentParser()
parser.add_argument('foo')
parser.add_argument('--extra', nargs=argparse.REMAINDER)
parser.add_argument('--option')

args = parser.parse_args()

[--extra ...] is not at all last in the usage line:

$ ./test.py -h
usage: test.py [-h] [--extra ...] [--option OPTION] foo

positional arguments:
  foo

options:
  -h, --help       show this help message and exit
  --extra ...
  --option OPTION

Your environment

• archlinux/amd64
• Tested on python 3.10.4 and also on 3.7.7 and 3.8.7.

執行報告中的最小 argparse 腳本，並檢查 ArgumentParser 如何為使用 nargs=argparse.REMAINDER 的 add_argument 呼叫格式化 usage 行。確認目前的順序，並找出相關的 argparse usage 格式化測試或進入點。完成條件是：remainder 選項出現在 usage 輸出中的位置引數之後，同時不影響其他選項的順序。