CentOS升级Python2到Python3

centos 的系统默认是使用python2进行管理和yum升级 所以要把原来的指定到python2

[root@VM_0_4_centos ~]# vim /usr/bin/yum
[root@VM_0_4_centos ~]# vim /usr/libexec/urlgrabber-ext-down

#!/usr/bin/python2.7
注意不能改成python2 要改成python2.7

可以简单看下Python的环境

[root@VM_0_4_centos ~]# whereis python
python: /usr/bin/python /usr/bin/python2.7-config /usr/bin/python2.7 /usr/lib/python2.7 /usr/lib64/python2.7 /etc/python /usr/include/python2.7 /usr/share/man/man1/python.1.gz
[root@VM_0_4_centos ~]# ls -alh /usr/bin/python
lrwxrwxrwx 1 root root 7 Jun 22 17:14 /usr/bin/python -> python2
[root@VM_0_4_centos ~]# whereis python2
python2: /usr/bin/python2 /usr/bin/python2.7-config /usr/bin/python2.7 /usr/lib/python2.7 /usr/lib64/python2.7 /usr/include/python2.7 /usr/share/man/man1/python2.1.gz
[root@VM_0_4_centos ~]#

把上面两个文件的python 改成python2以后 就可以安装python3了

目前默认yum源是 python36 如果要安装3.7 需要下载源码包了 这里就省事了 毕竟不就结这个具体的版本

yum install -y  python36

yum install -y python36-setuptools

yum install -y python36-pip

设置成默认的python

[root@VM_0_4_centos bin]# ln -s /usr/bin/python3.6 /usr/bin/python
[root@VM_0_4_centos bin]# python
Python 3.6.8 (default, Apr  2 2020, 13:34:55) 
[GCC 4.8.5 20150623 (Red Hat 4.8.5-39)] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> 

没啥技术含量，但是我这脑子总是记不住，今天说不能再这样了，不能在一个坑里一直跌到啊。