参考文章：centos7+django+python3+mysql+阿里云部署项目全流程

因为我们要安装python3版本，所以python要指向python3才行，目前还没有安装python3，先备份,备份之前先安装相关包，用于下载编译python3

1.python3.7的依赖:这几个包必须得安装，否则安装python3时可能会出现各种错误.

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

2.编译安装

[root@zhoushuai ~]# wget https://www.python.org/ftp/python/3.7.3/Python-3.7.3.tgz
[root@zhoushuai ~]# tar -zxvf Python-3.7.3.tgz
[root@zhoushuai ~]# cd Python-3.7.3
[root@zhoushuai  Python-3.7.3]# ./configure prefix=/usr/local/python3
[root@zhoushuai  Python-3.7.3]# make && make install
[root@zhoushuai  Python-3.7.3]# echo $?
0
[root@zhoushuai  Python-3.7.3]# ls /usr/local/python3/
bin  include  lib  share
[root@zhoushuai  Python-3.7.3]# 

3.实现python3和python2的共存

[root@zhoushuai ~]# cd /usr/bin
[root@zhoushuai bin]# mv py
pydoc             python            python2           python2.7         python2.7-config  python2-config    python-config
[root@zhoushuai bin]# mv python python.bak #先备份
[root@zhoushuai bin]# 
[root@zhoushuai bin]# ls python*
python2  python2.7  python2.7-config  python2-config  python.bak  python-config
[root@zhoushuai bin]#

[root@zhoushuai ~]# ln -s /usr/local/python3/bin/py
pydoc3             python3            python3.7-config   python3.7m-config  pyvenv             
pydoc3.7           python3.7          python3.7m         python3-config     pyvenv-3.7         
[root@zhoushuai ~]# ln -s /usr/local/python3/bin/python3 /usr/bin/python
[root@zhoushuai ~]# ls /usr/bin/python
/usr/bin/python
[root@zhoushuai ~]# ll /usr/bin/python
lrwxrwxrwx 1 root root 30 May 29 10:40 /usr/bin/python -> /usr/local/python3/bin/python3
[root@zhoushuai ~]# python -V
Python 3.7.3
[root@zhoushuai  ~]# python2 -V
Python 2.7.5
[root@zhoushuai ~]# 

4.因为执行yum需要python2版本，所以我们还要修改yum的配置，执行：

把#! /usr/bin/python修改为#! /usr/bin/python2

[root@zhoushuai ~]# vim /usr/bin/yum

image.png

5./usr/libexec/urlgrabber-ext-down 同上修改

文件里面的#! /usr/bin/python 也要修改为#! /usr/bin/python2

[root@zhoushuai ~]# vim /usr/libexec/urlgrabber-ext-down