使用pip3 install pymysql直接在线安装PyMySQL驱动

使用pip3 install pymysql时，提示：Successfully installed pymysql-0.10.0。同时，出现pip版本更新警告，根据警告更新了pip3后，再次安装pymysql，提示“已满足要求”。
安装过程如下：

[root@localhost~]# pip3 install pymysql
Collecting pymysql
  Downloading PyMySQL-0.10.0-py2.py3-none-any.whl (47 kB)
     |████████████████████████████████| 47 kB 23 kB/s 
Installing collected packages: pymysql
Successfully installed pymysql-0.10.0
WARNING: You are using pip version 20.2.1; however, version 20.2.2 is available.
You should consider upgrading via the '/usr/local/python3/bin/python3 -m pip install --upgrade pip' command.
[root@localhost~]# /usr/local/python3/bin/python3 -m pip install --upgrade pip
Collecting pip
  Downloading pip-20.2.2-py2.py3-none-any.whl (1.5 MB)
     |████████████████████████████████| 1.5 MB 5.6 kB/s 
Installing collected packages: pip
  Attempting uninstall: pip
    Found existing installation: pip 20.2.1
    Uninstalling pip-20.2.1:
      Successfully uninstalled pip-20.2.1
Successfully installed pip-20.2.2
[root@localhost~]# pip3 install pymysql
Requirement already satisfied: pymysql in /usr/local/python3/lib/python3.8/site-packages (0.10.0)