centos7中python2升级到python3

首先最好先换yum源，方便后续操作
换源方法
https://juejin.cn/post/6883839564985663496
1，在usr文件夹里建立文件
(1)进入目录

cd /usr/local

(2)创建文件夹

mkdir python3

2，安装依赖包

yum install -y libffi-devel
yum install zlib-devel bzip2-devel openssl-devel ncurses-devel sqlite-devel readline-devel tk-devel gcc libffi-devel

3，在home目录下建立文件
(1)进入目录

cd /home/python3

(2)创建文件夹

mkdir python3

(3)进入目录

cd python3

4，下载并安装python
(1)下载

wget  https://www.python.org/ftp/python/3.7.3/Python-3.7.3.tgz

(2)解压

tar -zvxf Python-3.7.3.tgz

(3)进入解压后的目录

cd Python-3.7.3

(4)编译

./configure --prefix=/usr/local/python3

(5)安装

make && make install

5，安装支持python的gcc，要不然python3无法运行
(1)下载gcc

yum install make gcc gcc-c++ zlib* openssl* libffi-devel -y

(2)执行

./configure

(3)安装

make && make install

6，备份python2
(1)将原来的python软链接指向python3

mv /usr/bin/python /usr/bin/python.bak

(2)创建新的软连接

ln -s /usr/local/python/bin/python3.7 /usr/bin/python

7，yum备份
编辑这两个文件，将/usr/local/python改成/usr/local/python2
 

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

参考链接

Centos7升级Python2到Python3 - 掘金

CentOS升级Python详解_centos 升级python_时空无限的博客-CSDN博客