用pip安装一些包时遇到 SNIMissingWarning + InsecurePlatformWarning (unbuntu 12.04.5/python 2.7.3/pip 9.0.1)
具体细节如下，请高手指点，多谢！
aiboat@ubuntu:/usr/local/bin$ sudo -H pip install pyopenssl ndg-httpsclient pyasn1 --upgrade /usr/local/lib/python2.7/dist-packages/pip/vendor/requests/packages/urllib3/util/ssl.py:318: SNIMissingWarning: An HTTPS request has been made, but the SNI (Subject Name Indication) extension to TLS is not available on this platform. This may cause the server to present an incorrect TLS certificate, which can cause validation failures. You can upgrade to a newer version of Python to solve this. For more information, see https://urllib3.readthedocs.io/en/latest/security.html#snimissingwarning. SNIMissingWarning /usr/local/lib/python2.7/dist-packages/pip/vendor/requests/packages/urllib3/util/ssl.py:122: InsecurePlatformWarning: A true SSLContext object is not available. This prevents urllib3 from configuring SSL appropriately and may cause certain SSL connections to fail. You can upgrade to a newer version of Python to solve this. For more information, see https://urllib3.readthedocs.io/en/latest/security.html#insecureplatformwarning. InsecurePlatformWarning Requirement already up-to-date: pyopenssl in /usr/local/lib/python2.7/dist-packages Requirement already up-to-date: ndg-httpsclient in /usr/local/lib/python2.7/dist-packages Requirement already up-to-date: pyasn1 in /usr/local/lib/python2.7/dist-packages Requirement already up-to-date: cryptography>=1.9 in /usr/local/lib/python2.7/dist-packages (from pyopenssl) Requirement already up-to-date: six>=1.5.2 in /usr/local/lib/python2.7/dist-packages (from pyopenssl) Requirement already up-to-date: asn1crypto>=0.21.0 in /usr/local/lib/python2.7/dist-packages (from cryptography>=1.9->pyopenssl) Requirement already up-to-date: cffi>=1.7 in /usr/local/lib/python2.7/dist-packages (from cryptography>=1.9->pyopenssl) Requirement already up-to-date: ipaddress in /usr/local/lib/python2.7/dist-packages (from cryptography>=1.9->pyopenssl) Requirement already up-to-date: enum34 in /usr/local/lib/python2.7/dist-packages (from cryptography>=1.9->pyopenssl) Requirement already up-to-date: idna>=2.1 in /usr/local/lib/python2.7/dist-packages (from cryptography>=1.9->pyopenssl) Requirement already up-to-date: pycparser in /usr/local/lib/python2.7/dist-packages (from cffi>=1.7->cryptography>=1.9->pyopenssl)