CentOS6.8安装python3.8

一、切记，不要删除自带的python（如果删除则进行本节）

如果删除自带的python2，编译python安装文件时需要gcc，而gcc又需要python支持，如果已经删除，则需要重新安装python和yum。
下载镜像地址：https://vault.centos.org/6.8/os/x86_64/Packages/

1.1安装原有python

1.创建目录

mkdir /usr/local/src/python

2.切换到python文件夹

cd /usr/local/src/python

3.在镜像上下载python2文件（–no-check-certificate解决网站证书不安全问题）

wget http://vault.centos.org/6.8/os/x86_64/Packages/python-2.6.6-64.el6.x86_64.rpm --no-check-certificate
wget http://vault.centos.org/6.8/os/x86_64/Packages/python-iniparse-0.3.1-2.1.el6.noarch.rpm --no-check-certificate
wget http://vault.centos.org/6.8/os/x86_64/Packages/python-pycurl-7.19.0-9.el6.x86_64.rpm --no-check-certificate
wget http://vault.centos.org/6.8/os/x86_64/Packages/python-devel-2.6.6-64.el6.x86_64.rpm --no-check-certificate
wget http://vault.centos.org/6.8/os/x86_64/Packages/python-libs-2.6.6-64.el6.x86_64.rpm --no-check-certificate
wget http://vault.centos.org/6.8/os/x86_64/Packages/python-urlgrabber-3.9.1-11.el6.noarch.rpm --no-check-certificate
wget http://vault.centos.org/6.8/os/x86_64/Packages/rpm-python-4.8.0-55.el6.x86_64.rpm --no-check-certificate

4.安装原有python2

cd /usr/local/src/python
rpm -ivh python-* rpm-python-*

5.检验是否安装成功

[root@centos python]# python -V
Python 2.6.6

1.2 安装原有yum
1.创建目录

mkdir /usr/local/src/yum

2.切换到yum文件夹

cd /usr/local/src/yum

3.在镜像上下载yum文件：https://vault.centos.org/6.8/os/x86_64/Packages/

wget https://vault.centos.org/centos/6.10/os/x86_64/Packages/yum-3.2.29-81.el6.centos.noarch.rpm --no-check-certificate
wget https://vault.centos.org/centos/6.10/os/x86_64/Packages/yum-metadata-parser-1.1.2-16.el6.x86_64.rpm  --no-check-certificate
wget https://vault.centos.org/centos/6.10/os/x86_64/Packages/yum-plugin-fastestmirror-1.1.30-41.el6.noarch.rpm  --no-check-certificate

4.安装yum

rpm -ivh yum-*

5.检验是否安装成功

bash[root@centos python]# yum
你需要给出命令Usage: yum [options] COMMANDList of Commands:check          Check for problems in the rpmdb
check-update   检查是否有软件包更新
clean          删除缓存的数据
deplist        列出软件包的依赖关系
distribution-synchronization Synchronize installed packages to the latest available versions
downgrade      downgrade a package

到此python2和yum安装成功，如果系统不能联网，也可以在镜像上下载之后上传完成安装

二、安装python3.8

1.下载python3.8
下载镜像：https://www.python.org/ftp/python/3.8.3/
下载python-3.8.3.tar.xz，将文件放在/opt目录下
2.解压文件

tar xvf Python-3.8.3.tar.xz

解压后的文件为Python-3.8.3
3.安装python3
进入解压后的安装包

cd /opt/Python-3.8.3

运行安装文件,–prefix=/opt/python3.8为设置安装路径

./configure --prefix=/opt/python3.8

如果运行不成功，如果是缺少gcc文件解决方式，则到第三节解决

如果运行成功，则继续输入：

make && make install

如果运行不成功，报错：zipimport.ZipImportError: can‘t decompress data； zlib not available
则运行

yum -y install zlib*

（yum不能使用时第四节解决）
至此，python3.8安装完成，但是还需要安装pip和wheel
4.安装pip和wheel
依次运行

yum -y install epel-release
yum -y install python-pip python-wheel

5.设置软连接

ln -s /opt/python3.8/bin/python3.8 /usr/bin/python3
ln -s /opt/python3.8/bin/pip3 /usr/bin/pip3

6.设置环境变量
编辑环境变量文件

vim /etc/profile

将最后改为：
export PATH=/usr/local/sbin:/usr/local/bin:usr/bin:/usr/bin:/root/bin:/opt/python3.8/bin
将环境变量生效

vim /etc/profile

7.检验是否安装成功

[root@centos ~]# python3 -V
Python 3.8.3

三、缺少gcc文件解决方式

1.创建目录

mkdir /usr/local/src/gcc

2.下载
下载镜像：https://vault.centos.org/6.8/os/x86_64/Packages/
进入目录

cd /usr/local/src/gcc

下载文件：

wget https://vault.centos.org/centos/6.10/os/x86_64/Packages/ppl-0.10.2-11.el6.x86_64.rpm --no-check-certificate
wget https://vault.centos.org/centos/6.10/os/x86_64/Packages/cloog-ppl-0.15.7-1.2.el6.x86_64.rpm --no-check-certificate
wget https://vault.centos.org/centos/6.10/os/x86_64/Packages/mpfr-2.4.1-6.el6.x86_64.rpm --no-check-certificate
wget https://vault.centos.org/centos/6.10/os/x86_64/Packages/cpp-4.4.7-17.el6.x86_64.rpm --no-check-certificate
wget https://vault.centos.org/centos/6.10/os/x86_64/Packages/kernel-headers-2.6.32-642.el6.x86_64.rpm --no-check-certificate
wget https://vault.centos.org/centos/6.10/os/x86_64/Packages/glibc-headers-2.12-1.192.el6.x86_64.rpm --no-check-certificate
wget https://vault.centos.org/centos/6.10/os/x86_64/Packages/glibc-devel-2.12-1.192.el6.x86_64.rpm --no-check-certificate
wget https://vault.centos.org/centos/6.10/os/x86_64/Packages/gcc-4.4.7-17.el6.x86_64.rpm --no-check-certificate
wget https://vault.centos.org/centos/6.10/os/x86_64/Packages/libstdc++-devel-4.4.7-17.el6.x86_64.rpm --no-check-certificate
wget https://vault.centos.org/centos/6.10/os/x86_64/Packages/gcc-c++-4.4.7-17.el6.x86_64.rpm --no-check-certificate

3.运行文件
注意依次运行：


rpm -ivh ppl-0.10.2-11.el6.x86_64.rpm
rpm -ivh cloog-ppl-0.15.7-1.2.el6.x86_64.rpm
rpm -ivh mpfr-2.4.1-6.el6.x86_64.rpm
rpm -ivh cpp-4.4.7-17.el6.x86_64.rpm
rpm -ivh kernel-headers-2.6.32-642.el6.x86_64.rpm
rpm -ivh glibc-headers-2.12-1.192.el6.x86_64.rpm
rpm -ivh glibc-devel-2.12-1.192.el6.x86_64.rpm
rpm -ivh gcc-4.4.7-17.el6.x86_64.rpm
rpm -ivh libstdc++-devel-4.4.7-17.el6.x86_64.rpm
rpm -ivh gcc-c++-4.4.7-17.el6.x86_64.rpm

检验是否安装成功

[root@centos python]# gcc -v
使用内建 specs。
目标：x86_64-redhat-linux
配置为：../configure --prefix=/usr --mandir=/usr/share/man --infodir=/usr/share/info --with-bugurl=http://bugzilla.redhat.com/bugzilla --enable-bootstrap --enable-shared --enable-threads=posix --enable-checking=release --with-system-zlib --enable-__cxa_atexit --disable-libunwind-exceptions --enable-gnu-unique-object --enable-languages=c,c++,objc,obj-c++,java,fortran,ada --enable-java-awt=gtk --disable-dssi --with-java-home=/usr/lib/jvm/java-1.5.0-gcj-1.5.0.0/jre --enable-libgcj-multifile --enable-java-maintainer-mode --with-ecj-jar=/usr/share/java/eclipse-ecj.jar --disable-libjava-multilib --with-ppl --with-cloog --with-tune=generic --with-arch_32=i686 --build=x86_64-redhat-linux
线程模型：posix
gcc 版本 4.4.7 20120313 (Red Hat 4.4.7-17) (GCC)

四、yum不能使用的问题

1.关闭fastestmirrors
进去编辑

vim /etc/yum/pluginconf.d/fastestmirror.conf

修改其中的enable=0
2.备份repo

mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.bak

3.替换为国内镜像源（阿里）

curl -o /etc/yum.repos.d/CentOS-Base.repo https://www.xmpan.com/Centos-6-Vault-Aliyun.repo