Centos7安装Python3.8详细教程
安装编译相关工具

yum -y groupinstall "Development tools"
yum -y install zlib-devel bzip2-devel openssl-devel ncurses-devel sqlite-devel readline-devel tk-devel gdbm-devel db4-devel libpcap-devel xz-devel
yum install libffi-devel -y

下载python安装包

wget https://www.python.org/ftp/python/3.8.3/Python-3.8.3.tgz
tar -zxvf  Python-3.8.3.tgz

编译安装python

mkdir /usr/local/python3 #创建编译安装目录
cd Python-3.8.3
./configure --prefix=/usr/local/python3
make && make install

安装过，出现下面两行就成功了

Installing collected packages: setuptools, pip
Successfully installed pip-19.2.3 setuptools-41.2.0

创建软连接

查看当前python软连接

ll /usr/bin/ |grep python

lrwxrwxrwx    1 root root         35 Feb 18 19:41 btpython -> /www/server/panel/pyenv/bin/python3
lrwxrwxrwx    1 root root          7 Apr 18 22:51 python -> python2
lrwxrwxrwx    1 root root          9 Apr 18 22:51 python2 -> python2.7
-rwxr-xr-x    1 root root       7144 Jun 28  2022 python2.7
-rwxr-xr-x    1 root root       1835 Jun 28  2022 python2.7-config
lrwxrwxrwx    1 root root         16 Apr 18 22:51 python2-config -> python2.7-config
lrwxrwxrwx    1 root root         14 Apr 18 22:51 python-config -> python2-config

默认系统安装的是python2.7
删除python软连接

rm -rf /usr/bin/python

配置软连接为python3

#添加python3的软链接 
ln -s /usr/local/python3/bin/python3 /usr/bin/python

这个时候看下python默认版本

python -V

删除默认pip软连接，并添加pip3新的软连接

rm -rf /usr/bin/pip
#添加 pip3 的软链接 
ln -s /usr/local/python3/bin/pip3 /usr/bin/pip

更改yum配置
因为其要用到python2才能执行，否则会导致yum不能正常使用（不管安装 python3的那个版本，都必须要做的）

vi /usr/bin/yum
把 #! /usr/bin/python 修改为 #! /usr/bin/python2.7 
vi /usr/libexec/urlgrabber-ext-down 
把 #! /usr/bin/python 修改为 #! /usr/bin/python2.7
vi /usr/bin/yum-config-manager
#!/usr/bin/python 改为 #!/usr/bin/python2.7