pip 版本： 9.0.3
pip查看软件版本号的方法：
pip show django
Name: Django
Version: 1.11.9
Summary: A high-level Python Web framework that encourages rapid development and clean, pragmatic design.
Home-page: https://www.djangoproject.com/
Author: Django Software Foundation
Author-email: foundation@djangoproject.com
License: BSD
Location: /usr/lib/python2.7/site-packages
Requires: pytz