我正在尝试通过自制软件安装Python 2，我收到以下错误：
$ brew install python
Error: python-python already installed
To install this version, first `brew unlink python`
按照这个建议给我
brew unlink python
Error: No such keg: /usr/local/Cellar/python
/ usr / local / Cellar中没有与Python相关的内容。我尝试过brew prune / doctor / update / cleanup并清除缓存无济于事。如何使用自制软件安装Python 2？