在 Python 请求中收到“403 客户端错误：需要 SNI”

Question

出乎意料的是，Python 代码上的 API“请求”开始出现此错误：

Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/usr/lib/python2.7/dist-packages/requests/api.py", line 55, in get
return request('get', url, **kwargs)
File "/usr/lib/python2.7/dist-packages/requests/api.py", line 44, in request
return session.request(method=method, url=url, **kwargs)
File "/usr/lib/python2.7/dist-packages/requests/sessions.py", line 455, in request
resp = self.send(prep, **send_kwargs)
File "/usr/lib/python2.7/dist-packages/requests/sessions.py", line 558, in send
r = adapter.send(request, **kwargs)
File "/usr/lib/python2.7/dist-packages/requests/adapters.py", line 385, in send
raise SSLError(e)
requests.exceptions.SSLError: [Errno 1] _ssl.c:510: error:14077438:SSL 
routines:SSL23_GET_SERVER_HELLO:tlsv1 alert internal error

在搜索了很多东西后，我找到了一些可供下载的软件包。但这也引发了错误：

所以，我注意到的主要事情是

无法获取 URL https://pypi.python.org/simple/pip/：403客户端错误：需要 SNI

请告知这是什么以及如何解决这个问题。提前致谢！