yolov5项目如何安装pycocotools?

部分人运行 pip install -r requirements.txt之后opencv-python和 pycocotools可能还是无法自动安装如下图：
报错：
WARNING: Retrying (Retry(total=4, connect=None, read=None, redirect=None, status=None)) after connection broken by ‘NewConnectionErro
r(’<pip._vendor.urllib3.connection.HTTPSConnection object at 0x00000230ADA562E0>: Failed to establish a new connection: [Errno 11001]
getaddrinfo failed’)’: /pypi/simple/opencv-python/

ERROR: Could not find a version that satisfies therequirement opencv-python (from versions: none)
ERROR: No matching distribution found for opencv-python

解决方法一：

手动pip install pycocotools和pip install opencv-python
注：如果这样就能安装就太好了，不用看下一个解决方法了。

解决方法二：

1安装pycocotools

链接：https://pan.baidu.com/s/19rFLqtOfcF8SAiQR3bIK_Q
提取码：rf2z
手动下载pycocotoolsb包

将这两个包放到：

安装成功

镜像安装opencv-python

在要安装的环境terminal里面输入：
镜像安装格式
pip install opencv-python -i <你的镜像url>

一般conda使用清华源即输入：
pip install opencv-python -i https://pypi.tuna.tsinghua.edu.cn/simple