Cent OS中Python2、Python3和yum的安装卸载

Cent OS系统默认自带有Python2版本，在正常情况下，是不需要重装的。往往有些时候，Python环境不可用，或者yum命令无法执行时，就可以通过重装来修复环境。

1.删除已有的Python

#rpm -qa|grep python|xargs rpm -ev --allmatches --nodeps

#whereis python |xargs rm -frv

#whereis python

2.删除已有的yum

#rpm -qa|grep yum|xargs rpm -ev --allmatches --nodeps

#whereis yum |xargs rm -frv

3. 创建两个目录用于存放Python和yum的rpm包

#mkdir /usr/local/src/python

#mkdir /usr/local/src/yum

4. 查到centOS的版本并下载相应的rpm包

#cat /etc/redhat-release

对应的rpm包下载网址：http://mirrors.ustc.edu.cn/centos/7.7.1908/os/x86_64/Packages/

http://mirrors.ustc.edu.cn/centos/7.7.1908/os/x86_64/Packages/python-2.7.5-86.el7.x86_64.rpm

http://mirrors.ustc.edu.cn/centos/7.7.1908/os/x86_64/Packages/python-devel-2.7.5-86.el7.x86_64.rpm

http://mirrors.ustc.edu.cn/centos/7.7.1908/os/x86_64/Packages/python-iniparse-0.4-9.el7.noarch.rpm

http://mirrors.ustc.edu.cn/centos/7.7.1908/os/x86_64/Packages/python-pycurl-7.19.0-19.el7.x86_64.rpm

http://mirrors.ustc.edu.cn/centos/7.7.1908/os/x86_64/Packages/python-setuptools-0.9.8-7.el7.noarch.rpm

http://mirrors.ustc.edu.cn/centos/7.7.1908/os/x86_64/Packages/python-libs-2.7.5-86.el7.x86_64.rpm

http://mirrors.ustc.edu.cn/centos/7.7.1908/os/x86_64/Packages/python-urlgrabber-3.10-9.el7.noarch.rpm

http://mirrors.ustc.edu.cn/centos/7.7.1908/os/x86_64/Packages/rpm-python-4.11.3-40.el7.x86_64.rpm

进入到python目录下

#cd /usr/local/src/python

将上面的rpm包下载到python目录

cd /usr/local/src/yum

http://mirrors.ustc.edu.cn/centos/7.7.1908/os/x86_64/Packages/yum-3.4.3-163.el7.centos.noarch.rpm

http://mirrors.ustc.edu.cn/centos/7.7.1908/os/x86_64/Packages/yum-metadata-parser-1.1.4-10.el7.x86_64.rpm

http://mirrors.ustc.edu.cn/centos/7.7.1908/os/x86_64/Packages/yum-utils-1.1.31-52.el7.noarch.rpm

http://mirrors.ustc.edu.cn/centos/7.7.1908/os/x86_64/Packages/yum-plugin-fastestmirror-1.1.31-52.el7.noarch.rpm

http://mirrors.ustc.edu.cn/centos/7.7.1908/os/x86_64/Packages/yum-plugin-protectbase-1.1.31-52.el7.noarch.rpm

http://mirrors.ustc.edu.cn/centos/7.7.1908/os/x86_64/Packages/yum-plugin-aliases-1.1.31-52.el7.noarch.rpm

5.安装python

#rpm -ivh python-* rpm-python-*

出现上面依赖包的解决方法：

#rpm -ivh python-* rpm-python-* --nodeps --force

输入#python 查看Python是否按照成功

6. 安装yum

#cd /usr/local/src/yum

#rpm -ivh yum-* --nodeps --force

7.安装Python3.8

# wget https://www.python.org/ftp/python/3.8.1/Python-3.8.1.tgz ！获取Python软件包

# tar -zxvf Python-3.8.1.tgz ！解压

# cd Python-3.8.1

# yum -y install libffi-devel zlib-devel bzip2-devel openssl-devel ncurses-devel sqlite-devel readline-devel tk-devel gcc make ！安装相关依赖

在 ./configure 操作前，先进行编码配置：

# export LANGUAGE=en_US.UTF-8

# export LANG=en_US.UTF-8

# export LC_ALL=en_US.UTF-8

# ./configure prefix=/usr/local/python38

# make && make install

建立软链接

# ln -s /usr/local/python38/bin/python3 /usr/local/bin/python3

# ln -s /usr/local/python38/bin/pip3 /usr/local/bin/pip3

8.将Cent OS 默认的Python版本更改为Python3

环境变量修改

# vi ~/.bashrc

添加下面path配置

PATH=$PATH:$HOME/bin:/usr/local/python38/bin

重载文件

source ~/.bashrc

更新Python的默认指向

# ls -l /usr/bin | grep python ！查看python命令指向

# sudo mv /usr/bin/python /usr/bin/python.bak !备份

# sudo ln -s /usr/local/bin/python3 /usr/bin/python ！更新

检查Python版本

9.更新yum文件，否则会运行不了

将两个文件的首行#!/usr/bin/python改为#!/usr/bin/python2 之前Python指向的Python文件

# vim /usr/bin/yum

# vim /usr/libexec/urlgrabber-ext-down

最后编辑于：2020.04.13 16:46:45