python 安装BeautifulSoup 出现一个问题

Question

D:\student\python\Lib\beautifulsoup4-4.5.1> setup.py install

usage: setup.py [global_opts] cmd1 [cmd1_opts] [cmd2 [cmd2_opts] ...]

   or: setup.py --help [cmd1 cmd2 ...]

   or: setup.py --help-commands

   or: setup.py cmd --help