关于python 2.7：无法通过pip安装包

cannot install packages through pip

Python：2.7.12

点数：8.1.1

当我sudo pip install pandas时，它显示如下：

Exception:

Traceback (most recent call last):

File"/usr/lib/python2.7/dist-packages/pip/basecommand.py", line 209, in main

status = self.run(options, args)

File"/usr/lib/python2.7/dist-packages/pip/commands/install.py", line 317, in run

requirement_set.prepare_files(finder)

File"/usr/lib/python2.7/dist-packages/pip/req/req_set.py", line 360, in prepare_files

ignore_dependencies=self.ignore_dependencies))

File"/usr/lib/python2.7/dist-packages/pip/req/req_set.py", line 512, in _prepare_file

finder, self.upgrade, require_hashes)

File"/usr/lib/python2.7/dist-packages/pip/req/req_install.py", line 273, in populate_link

self.link = finder.find_requirement(self, upgrade)

File"/usr/lib/python2.7/dist-packages/pip/index.py", line 442, in find_requirement

all_candidates = self.find_all_candidates(req.name)

File"/usr/lib/python2.7/dist-packages/pip/index.py", line 400, in find_all_candidates

for page in self._get_pages(url_locations, project_name):

File"/usr/lib/python2.7/dist-packages/pip/index.py", line 545, in _get_pages

page = self._get_page(location)
File"/usr/lib/python2.7/dist-packages/pip/index.py", line 648, in _get_page

return HTMLPage.get_page(link, session=self.session)

File"/usr/lib/python2.7/dist-packages/pip/index.py", line 757, in get_page

"Cache-Control":"max-age=600",

File"/usr/share/python-wheels/requests-2.9.1-py2.py3-none-any.whl/requests/sessions.py", line 480, in get

return self.request('GET', url, **kwargs)

File"/usr/lib/python2.7/dist-packages/pip/download.py", line 378, in request

return super(PipSession, self).request(method, url, *args, **kwargs)

File"/usr/share/python-wheels/requests-2.9.1-py2.py3-none-any.whl/requests/sessions.py", line 468, in request

resp = self.send(prep, **send_kwargs)

File"/usr/share/python-wheels/requests-2.9.1-py2.py3-none-any.whl/requests/sessions.py", line 576, in send

r = adapter.send(request, **kwargs)

File"/usr/share/python-wheels/CacheControl-0.11.5-py2.py3-none-any.whl/cachecontrol/adapter.py", line 46, in send

resp = super(CacheControlAdapter, self).send(request, **kw)

File"/usr/share/python-wheels/requests-2.9.1-py2.py3-none-any.whl/requests/adapters.py", line 376, in send

timeout=timeout

File"/usr/share/python-wheels/urllib3-1.13.1-py2.py3-none-any.whl/urllib3/connectionpool.py", line 610, in urlopen

_stacktrace=sys.exc_info()[2])

File"/usr/share/python-wheels/urllib3-1.13.1-py2.py3-none-any.whl/urllib3/util/retry.py", line 228, in increment

total -= 1

TypeError: unsupported operand type(s) for -=: 'Retry' and 'int'