需求:pip install利用国内豆瓣下载模块
C:\windows\system32>pip install beautifullsoup4 -i https://pypi.douban.com/simpl
e --trusted-host=pypi.douban.com
C:\windows\system32>pip install beautifullsoup4 -i https://pypi.douban.com/simpl
e --trusted-host=pypi.douban.com