Ubuntu系统Python3.7安装opencv-python3.4时遇legacy-install-failure错误

• 安装系统编译依赖包：

  sudo apt update
  sudo apt install -y build-essential cmake git libgtk2.0-dev pkg-config libavcodec-dev libavformat-dev libswscale-dev
  sudo apt install -y python3-dev python3-numpy libtbb2 libtbb-dev libjpeg-dev libpng-dev libtiff-dev libjasper-dev libdc1394-22-dev
  

• 强制使用预编译wheel包安装：

  pip install opencv-python==3.4.0.14 --only-binary :all:
  

  若仍失败，可手动下载对应Python3.7的manylinux1_x86_64版本wheel文件，本地执行安装：

  pip install opencv_python-3.4.0.14-cp37-cp37m-manylinux1_x86_64.whl
  

• 降级setuptools适配旧版opencv编译逻辑：

  pip install setuptools==45.0.0
  pip install opencv-python==3.4.0.14
  

• 若使用conda环境，尝试通过conda安装：

  conda install -c conda-forge opencv=3.4.0
  

内容的提问来源于stack exchange，提问作者basti07