错误pip不使用不同python版本的代理

Question

我已经安装了python 2.7和3.9我的操作系统Windows 10如果我启动pip在python 2.7子文件夹的脚本中安装一个包，那么它会正常工作如果我尝试在其他位置安装，我会遇到以下错误：

pip install <package> --proxy http://myproxy:port/
ERROR: Exception:
Traceback (most recent call last):
  File "c:\users\linosa\appdata\local\programs\python\python39\lib\site-packages\pip\_internal\cli\base_command.py", line 228, in _main
    status = self.run(options, args)
  File "c:\users\linosa\appdata\local\programs\python\python39\lib\site-packages\pip\_internal\cli\req_command.py", line 182, in wrapper
    return func(self, options, args)
  File "c:\users\linosa\appdata\local\programs\python\python39\lib\site-packages\pip\_internal\commands\install.py", line 323, in run
    requirement_set = resolver.resolve(
  File "c:\users\linosa\appdata\local\programs\python\python39\lib\site-packages\pip\_internal\resolution\legacy\resolver.py", line 183, in resolve
    discovered_reqs.extend(self._resolve_one(requirement_set, req))
  File "c:\users\linosa\appdata\local\programs\python\python39\lib\site-packages\pip\_internal\resolution\legacy\resolver.py", line 388, in _resolve_one
    abstract_dist = self._get_abstract_dist_for(req_to_install)
  File "c:\users\linosa\appdata\local\programs\python\python39\lib\site-packages\pip\_internal\resolution\legacy\resolver.py", line 339, in _get_abstract_dist_for
    self._populate_link(req)
  File "c:\users\linosa\appdata\local\programs\python\python39\lib\site-packages\pip\_internal\resolution\legacy\resolver.py", line 305, in _populate_link
    req.link = self._find_requirement_link(req)
  File "c:\users\linosa\appdata\local\programs\python\python39\lib\site-packages\pip\_internal\resolution\legacy\resolver.py", line 270, in _find_requirement_link
    best_candidate = self.finder.find_requirement(req, upgrade)
  File "c:\users\linosa\appdata\local\programs\python\python39\lib\site-packages\pip\_internal\index\package_finder.py", line 898, in find_requirement
    best_candidate_result = self.find_best_candidate(
  File "c:\users\linosa\appdata\local\programs\python\python39\lib\site-packages\pip\_internal\index\package_finder.py", line 881, in find_best_candidate
    candidates = self.find_all_candidates(project_name)
  File "c:\users\linosa\appdata\local\programs\python\python39\lib\site-packages\pip\_internal\index\package_finder.py", line 825, in find_all_candidates
    package_links = self.process_project_url(
  File "c:\users\linosa\appdata\local\programs\python\python39\lib\site-packages\pip\_internal\index\package_finder.py", line 790, in process_project_url
    html_page = self._link_collector.fetch_page(project_url)
  File "c:\users\linosa\appdata\local\programs\python\python39\lib\site-packages\pip\_internal\index\collector.py", line 643, in fetch_page
    return _get_html_page(location, session=self.session)
  File "c:\users\linosa\appdata\local\programs\python\python39\lib\site-packages\pip\_internal\index\collector.py", line 455, in _get_html_page
    resp = _get_html_response(url, session=session)
  File "c:\users\linosa\appdata\local\programs\python\python39\lib\site-packages\pip\_internal\index\collector.py", line 152, in _get_html_response
    resp = session.get(
  File "c:\users\linosa\appdata\local\programs\python\python39\lib\site-packages\pip\_vendor\requests\sessions.py", line 543, in get
    return self.request('GET', url, **kwargs)
  File "c:\users\linosa\appdata\local\programs\python\python39\lib\site-packages\pip\_internal\network\session.py", line 421, in request
    return super(PipSession, self).request(method, url, *args, **kwargs)
  File "c:\users\linosa\appdata\local\programs\python\python39\lib\site-packages\pip\_vendor\requests\sessions.py", line 530, in request
    resp = self.send(prep, **send_kwargs)
  File "c:\users\linosa\appdata\local\programs\python\python39\lib\site-packages\pip\_vendor\requests\sessions.py", line 643, in send
    r = adapter.send(request, **kwargs)
  File "c:\users\linosa\appdata\local\programs\python\python39\lib\site-packages\pip\_vendor\cachecontrol\adapter.py", line 53, in send
    resp = super(CacheControlAdapter, self).send(request, **kw)
  File "c:\users\linosa\appdata\local\programs\python\python39\lib\site-packages\pip\_vendor\requests\adapters.py", line 412, in send
    conn = self.get_connection(request.url, proxies)
  File "c:\users\linosa\appdata\local\programs\python\python39\lib\site-packages\pip\_vendor\requests\adapters.py", line 309, in get_connection
    proxy_manager = self.proxy_manager_for(proxy)
  File "c:\users\linosa\appdata\local\programs\python\python39\lib\site-packages\pip\_vendor\requests\adapters.py", line 193, in proxy_manager_for
    manager = self.proxy_manager[proxy] = proxy_from_url(
  File "c:\users\linosa\appdata\local\programs\python\python39\lib\site-packages\pip\_vendor\urllib3\poolmanager.py", line 492, in proxy_from_url
    return ProxyManager(proxy_url=url, **kw)
  File "c:\users\linosa\appdata\local\programs\python\python39\lib\site-packages\pip\_vendor\urllib3\poolmanager.py", line 429, in __init__
    raise ProxySchemeUnknown(proxy.scheme)
pip._vendor.urllib3.exceptions.ProxySchemeUnknown: Not supported proxy scheme None

感谢你的帮助 提前谢谢 再见