错误pip无法与具有不同python版本的代理一起使用

如何解决错误pip无法与具有不同python版本的代理一起使用

如果我启动pip以在python 2.7子文件夹的脚本中安装软件包，则我已经在操作系统Windows 10中安装了python 2.7和3.9，如果我尝试在其他位置进行安装，则会正常工作，我得到以下错误：

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,*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",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

每一个帮助都是值得的 提前致谢 巧