1. Tsinghua source address: https://pypi.tuna.tsinghua.edu.cn/simple/
2. Alibaba Cloud: http://mirrors.aliyun.com/pypi/simple/
3. University of Science and Technology of China: http://mirrors.aliyun.com/pypi/simple/
4. University of Science and Technology of China: http://pypi.mirrors.ustc.edu.cn/simple/
5. Douban: https://pypi.doubanio.com/simple
Use the mirror source to install the package: pip install package name -i https://pypi.doubanio.com/simple
例如：pip install -r requirements.txt -i https://pypi.doubanio.com/simple