已卸载并安装python，现在面临pip问题

我使用mac，最近我从python2切换到了python3。由于某些依赖性问题，我无法在笔记本电脑上安装jupyter。经过多次尝试和错误，我刚刚卸载了Python 3，并用brew安装了它

我使用以下指南卸载

我再次安装了jupyter，现在我面临这个问题：

$pip安装--索引url'..'--受信任主机'..'jupyter

这就是我通常在防火墙后面的笔记本电脑上安装软件包的方式，它可以正常工作。但现在我得到了以下例外：

ERROR: Exception:
Traceback (most recent call last):
  File "/usr/local/lib/python3.7/site-packages/pip/_internal/cli/base_command.py", line 153, in _main
    status = self.run(options, args)
  File "/usr/local/lib/python3.7/site-packages/pip/_internal/commands/install.py", line 382, in run
    resolver.resolve(requirement_set)
  File "/usr/local/lib/python3.7/site-packages/pip/_internal/legacy_resolve.py", line 201, in resolve
    self._resolve_one(requirement_set, req)
  File "/usr/local/lib/python3.7/site-packages/pip/_internal/legacy_resolve.py", line 365, in _resolve_one
    abstract_dist = self._get_abstract_dist_for(req_to_install)
  File "/usr/local/lib/python3.7/site-packages/pip/_internal/legacy_resolve.py", line 311, in _get_abstract_dist_for
    req.populate_link(self.finder, upgrade_allowed, self.require_hashes)
  File "/usr/local/lib/python3.7/site-packages/pip/_internal/req/req_install.py", line 225, in populate_link
    self.link = finder.find_requirement(self, upgrade)
  File "/usr/local/lib/python3.7/site-packages/pip/_internal/index.py", line 879, in find_requirement
    req.name, specifier=req.specifier, hashes=hashes,
  File "/usr/local/lib/python3.7/site-packages/pip/_internal/index.py", line 861, in find_best_candidate
    candidates = self.find_all_candidates(project_name)
  File "/usr/local/lib/python3.7/site-packages/pip/_internal/index.py", line 791, in find_all_candidates
    collected_links = self._link_collector.collect_links(project_name)
  File "/usr/local/lib/python3.7/site-packages/pip/_internal/collector.py", line 541, in collect_links
    for page in self._get_pages(url_locations):
  File "/usr/local/lib/python3.7/site-packages/pip/_internal/collector.py", line 493, in _get_pages
    page = _get_html_page(location, session=self.session)
  File "/usr/local/lib/python3.7/site-packages/pip/_internal/collector.py", line 339, in _get_html_page
    resp = _get_html_response(url, session=session)
  File "/usr/local/lib/python3.7/site-packages/pip/_internal/collector.py", line 146, in _get_html_response
    "Cache-Control": "max-age=0",
  File "/usr/local/lib/python3.7/site-packages/pip/_vendor/requests/sessions.py", line 546, in get
    return self.request('GET', url, **kwargs)
  File "/usr/local/lib/python3.7/site-packages/pip/_internal/network/session.py", line 426, in request
    return super(PipSession, self).request(method, url, *args, **kwargs)
  File "/usr/local/lib/python3.7/site-packages/pip/_vendor/requests/sessions.py", line 533, in request
    resp = self.send(prep, **send_kwargs)
  File "/usr/local/lib/python3.7/site-packages/pip/_vendor/requests/sessions.py", line 646, in send
    r = adapter.send(request, **kwargs)
  File "/usr/local/lib/python3.7/site-packages/pip/_vendor/requests/adapters.py", line 412, in send
    conn = self.get_connection(request.url, proxies)
  File "/usr/local/lib/python3.7/site-packages/pip/_vendor/requests/adapters.py", line 309, in get_connection
    proxy_manager = self.proxy_manager_for(proxy)
  File "/usr/local/lib/python3.7/site-packages/pip/_vendor/requests/adapters.py", line 199, in proxy_manager_for
    **proxy_kwargs)
  File "/usr/local/lib/python3.7/site-packages/pip/_vendor/urllib3/poolmanager.py", line 470, in proxy_from_url
    return ProxyManager(proxy_url=url, **kw)
  File "/usr/local/lib/python3.7/site-packages/pip/_vendor/urllib3/poolmanager.py", line 420, in __init__
    raise ProxySchemeUnknown(proxy.scheme)
pip._vendor.urllib3.exceptions.ProxySchemeUnknown: Not supported proxy scheme None

我已经设置了代理，可以使用

env

查看它。我也试过：

export http_proxy="http://<hostname>:<port>"
export https_proxy="https://<hostname>:<port>"

导出http\u proxy=“http://:” 导出https_proxy=“https://:” 似乎什么都没用

---

任何建议都会有帮助。

最后，帮助的是

取消设置https\u proxy http\u proxy

也许这是相关的？我尝试了

--proxy

，但没有用。