centos 7.x 升级python2.7 到python3.9_centos7 python2.7 升级 python3.9

1. 安装依赖关系
 

yum -y install gcc python36-devel bzip2-devel sqlite-devel openssl-devel readline-devel xz-devel xz-devel tk-devel gdbm-devel libffi-devel

2. 下载和安装python包#

cd /usr/local/src
wget https://www.python.org/ftp/python/3.9.5/Python-3.9.5.tgz
tar zxvf Python-3.9.5.tgz
cd Python-3.9.5/
./configure --prefix=/usr/local/python3.9 --with-ssl
make && make install

3. 修改软连接

ln -fs /usr/local/python3.9/bin/python3.9 /usr/bin/python
ln -fs /usr/local/python3.9/bin/python3.9 /usr/bin/python3
ln -fs /usr/local/python3.9/bin/pip3.9 /usr/bin/pip
ln -fs /usr/local/python3.9/bin/pip3.9 /usr/bin/pip3

5.修改yum文件 

第一行改都修改为: (原因是安装了python3.8,CentOS 7.X 自带的yum采用的是python2.X，当系统将python升级到2.7 或3.X后，出现语法解释错误)

需要修改的文件：

/usr/bin/yum
/usr/libexec/urlgrabber-ext-down

把第一行 #!/usr/bin/python 改成 #!/usr/bin/python2

sed -i 's/\/usr\/bin\/python/\/usr\/bin\/python2/g' /usr/bin/yum
sed -i 's/\/usr\/bin\/python/\/usr\/bin\/python2/g'  /usr/libexec/urlgrabber-ext-down
sed -i 's/\/usr\/bin\/python/\/usr\/bin\/python2/g' /usr/bin/yum-config-manager

6.升级pip

python -m pip install --upgrade pip