pip无法使用

pip更新以后遇到一个问题

D:\Python27\lib\site-packages\pip-9.0.3-py2.7.egg\pip\_vendor\urllib3\util\ssl_.
py:339: SNIMissingWarning: An HTTPS request has been made, but the SNI (Subject
Name Indication) extension to TLS is not available on this platform. This may ca
use the server to present an incorrect TLS certificate, which can cause validati
on failures. You can upgrade to a newer version of Python to solve this. For mor
e information, see https://urllib3.readthedocs.io/en/latest/advanced-usage.html#
ssl-warnings
SNIMissingWarning
D:\Python27\lib\site-packages\pip-9.0.3-py2.7.egg\pip\_vendor\urllib3\util\ssl_.
py:137: InsecurePlatformWarning: A true SSLContext object is not available. This
prevents urllib3 from configuring SSL appropriately and may cause certain SSL c
onnections to fail. You can upgrade to a newer version of Python to solve this.
For more information, see https://urllib3.readthedocs.io/en/latest/advanced-usag
e.html#ssl-warnings
InsecurePlatformWarning

--------------------------------

解决方式：通过镜像下载，同时增加镜像信任授权

pip install -i http://pypi.douban.com/simple/ --trusted-host pypi.douban.com django==1.7