使用 pip 安装包的时候如 `pip install shadowsocks`,遇到了如下错误: ``` Could not import setuptools which is required to install from a source distribution. Please install setuptools. ``` 这是因为 python 环境中没有 setuptools 这个包。安装上就可以了: ``` $ pip install -U setuptools ``` 更具体的内容可在 Github Issues 查看: + [ImportError: No module named setuptools (add details to docs) ](https://github.com/pypa/pip/issues/1064)