我正在尝试安装python功能选择包：http://featureselection.asu.edu/
下载并解压缩scikit工具后，我按照说明尝试安装，如下所示：
$ pip install setup.py
我得错误说：
Could not find a version that satisfies the requirement
然后我尝试了：
pip install --user setup.py
但得到同样的错误。 我也尝试过：
brew install setup.py
得到了：
Error: No available formula with the name "setup.py"
==> Searching for a previously deleted formula...
Error: No previously deleted formula found.
==> Searching for similarly named formulae...
Error: No similarly named formulae found.
==> Searching taps...
Error: No formulae found in taps.
任何人都有过为什么会这样的经历？ 是因为我的python版本是3.5，而在需求中python是2.7？