在安装python3之前,我们先看一下当前的python版本
[root@asset-app01 /]# python --version Python 2.7.5
查看一下python的安装路径
[root@asset-app01 /]# rpm -ql python /usr/bin/pydoc /usr/bin/python /usr/bin/python2 /usr/bin/python2.7 /usr/libexec/platform-python /usr/share/doc/python-2.7.5 /usr/share/doc/python-2.7.5/LICENSE /usr/share/doc/python-2.7.5/README /usr/share/man/man1/python.1.gz /usr/share/man/man1/python2.1.gz /usr/share/man/man1/python2.7.1.gz
可以看出python是安装在/usr/bin目录中,看上去好像有三个版本,使用 ll 命令再看一下
[root@asset-app01 /]# ll usr/bin | grep python lrwxrwxrwx 1 root root 27 Jun 25 2019 futurize -> /usr/bin/python2.7-futurize lrwxrwxrwx 1 root root 27 Jun 25 2019 futurize-2 -> /usr/bin/python2.7-futurize lrwxrwxrwx 1 root root 27 Jun 25 2019 futurize-2.7 -> /usr/bin/python2.7-futurize lrwxrwxrwx 1 root root 29 Jun 25 2019 pasteurize -> /usr/bin/python2.7-pasteurize lrwxrwxrwx 1 root root 29 Jun 25 2019 pasteurize-2 -> /usr/bin/python2.7-pasteurize lrwxrwxrwx 1 root root 29 Jun 25 2019 pasteurize-2.7 -> /usr/bin/python2.7-pasteurize lrwxrwxrwx. 1 root root 7 May 16 2019 python -> python2 lrwxrwxrwx. 1 root root 9 May 16 2019 python2 -> python2.7 -rwxr-xr-x. 1 root root 7216 Apr 9 2019 python2.7 -rwxr-xr-x 1 root root 304 May 3 2019 python2.7-futurize -rwxr-xr-x 1 root root 308 May 3 2019 python2.7-pasteurize
·可以看出其实只有一个版本python2.7, python和python2都是通过软连接的方式连接到python2.7
接下来我们安装python3
yum install python3 -y
这个时候查看python版本,发现还是python2.7的版本
[root@asset-app01 /]# python --version Python 2.7.5
这是因为python脚本是指向python2.7的软连接,我们需要将python文件改成指向python3的软连接
[root@localhost vagrant]# ll /usr/bin | grep python lrwxrwxrwx 1 root root 14 Feb 4 13:11 python -> /bin/python3.6 lrwxrwxrwx 1 root root 9 Feb 4 13:08 python2 -> python2.7 -rwxr-xr-x 1 root root 7216 Aug 7 09:52 python2.7 lrwxrwxrwx 1 root root 9 Feb 4 13:09 python3 -> python3.6 -rwxr-xr-x 2 root root 11408 Aug 8 02:29 python3.6 -rwxr-xr-x 2 root root 11408 Aug 8 02:29 python3.6m
将python文件改成指向python3的软连接(其实就是将新安装的python3作为默认的python编译器)
ln -snf /bin/python3.6 /bin/python
在查看python版本
[root@localhost vagrant]# python --version Python 3.6.8
总结: 上面说了一大堆,其实安装python3很简单,执行下面两句即可
安装python3
yum install python3 -y
将python3作为默认的python编译器
ln -snf /bin/python3.6 /bin/python
OK,python3安装完成
需要注意的是,安装完python3,并将python3作为默认编译器后,一些原来需要python2编译器的脚本命令将会无法使用,例如yum