If you live within the Great Wall Firewall, the access to the official source of PyPI is extremely unstable.
The xpip-mirror
mirror management can probe the delay of mirrors in the list and select the current optimal path.
root@zou:~# xpip-mirror list
name URL HOST PING(ms)
-------- ---------------------------------------- ----------------------------------------- ----------
ustc https://pypi.mirrors.ustc.edu.cn/simple pypi.mirrors.ustc.edu.cn (218.104.71.170) 8.3
baidu https://mirror.baidu.com/pypi/simple mirror.baidu.com (58.243.203.35) 15.7
aliyun https://mirrors.aliyun.com/pypi/simple mirrors.aliyun.com (119.167.250.248) 17.7
tsinghua https://pypi.tuna.tsinghua.edu.cn/simple pypi.tuna.tsinghua.edu.cn (101.6.15.130) 23.7
douban https://pypi.douban.com/simple pypi.douban.com (49.233.242.15) 32.0
pypi https://pypi.org/simple pypi.org (151.101.128.223) timeout
Suggest using the installation command:
pip install -i https://pypi.mirrors.ustc.edu.cn/simple <package-name>
root@zou:~# xpip-mirror now
https://mirrors.aliyun.com/pypi/simple
root@zou:~# xpip-mirror choice
Writing to /root/.config/pip/pip.conf
choice ustc: https://pypi.mirrors.ustc.edu.cn/simple
root@zou:~# xpip-mirror choice tsinghua
Writing to /root/.config/pip/pip.conf
choice tsinghua: https://pypi.tuna.tsinghua.edu.cn/simple