小结

在Red Hat 8.3中成功安装Python3.8.8和pip3。

问题

运行Python返回错误SyntaxError: future feature annotations is not defined，发现的问题是程序要求Python3.8解释器，然而现有安装版本是Python3.6。

解决

分别安装Python3.8.8和pip3，步骤如下：

删除Python3.6

[root@Master ~]]# yum remove python36

安装Python3.8和pip3

[root@Master ~]]# yum install python38
[root@Master ~]]# yum install python38-pip

设置默认Python和Pip版本

[root@Master ~]# cat ~/.bash_aliases 
alias python=/usr/bin/python3.8
alias python3=/usr/bin/python3.8
alias pip=/usr/bin/pip3
[root@Master ~]# source ~/.bash_aliases

检查成功设置：

[root@Master ~]# python
Python 3.8.8 (default, Aug 11 2021, 06:52:42) 
[GCC 8.5.0 20210514 (Red Hat 8.5.0-3)] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> exit()
[root@Master ~]# python -V
Python 3.8.8
[root@Master ~]# python3 -V
Python 3.8.8
[root@Master ~]# pip -V
pip 19.3.1 from /usr/lib/python3.8/site-packages/pip (python 3.8)
[root@Master ~]# pip3 -V
pip 19.3.1 from /usr/lib/python3.8/site-packages/pip (python 3.8)

参考

How to make python3.7 default
Red Hat: Chapter 38. Configuring the unversioned Python
How to change python default version from 2.7 to 3.7 on RHEL 7
Setting the Default python to python3
How to install pip in RHEL 8 / CentOS 8
Stackoverflow: SyntaxError: future feature annotations is not defined [duplicate]