安装detectron2时报错如下：
ERROR: Cannot uninstall 'pycocotools'. It is a distutils installed project and thus we cannot accurately determine which files belong to it which would lead to only a partial uninstall.
解决方法：
- 更新Pip
python -m pip install --upgrade pip -i https://pypi.tuna.tsinghua.edu.cn/simple
- 获取路径
pip install pycocotools
此时会得到类似这样的信息：
Requirement already satisfied: pycocotools in /home/dreamdeck/.local/lib/python3.6/site-packages (2.0)
可以知道我们的pkg在/home/dreamdeck/.local/lib/python3.6/site-packages
- 删除旧的
cd /home/dreamdeck/.local/lib/python3.6/site-packages
rm -rf pycocotools
rm -rf pycocotools-2.0-py3.7.egg-info
之后就可以安装新的pycocotools了。因为我需要安装detectron2，安装包内会自动执行安装pycocotools，所以直接执行
python -m pip install -e detectron2
