python 2x升级到3x

yum install python3

[root@test ~]# python -V

Python 2.7.5

[root@test ~]# python3 -V

Python 3.6.8

[root@test bin]# cd /usr/bin/

[root@test bin]# mv python python.bak

[root@test bin]# ln -s python3.6 python

[root@test bin]# python -V

Python 3.6.8

[root@test bin]# yum -y install lrzsz
  File "/usr/bin/yum", line 30
    except KeyboardInterrupt, e:
                            ^
SyntaxError: invalid syntax

vim /usr/bin/yum

vim /usr/libexec/urlgrabber-ext-down