如何在centos7中安装python3，,在安装python3

如何在centos7中安装python3，,在安装python3

在安装python3之前，我们先看一下当前的python版本

[[email protected] /]# python --versionPython 2.7.5

查看一下python的安装路径

[[email protected] /]# 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

[[email protected] /]# ll usr/bin | grep pythonlrwxrwxrwx    1 root root         27 Jun 25  2019 futurize -> /usr/bin/python2.7-futurizelrwxrwxrwx    1 root root         27 Jun 25  2019 futurize-2 -> /usr/bin/python2.7-futurizelrwxrwxrwx    1 root root         27 Jun 25  2019 futurize-2.7 -> /usr/bin/python2.7-futurizelrwxrwxrwx    1 root root         29 Jun 25  2019 pasteurize -> /usr/bin/python2.7-pasteurizelrwxrwxrwx    1 root root         29 Jun 25  2019 pasteurize-2 -> /usr/bin/python2.7-pasteurizelrwxrwxrwx    1 root root         29 Jun 25  2019 pasteurize-2.7 -> /usr/bin/python2.7-pasteurizelrwxrwxrwx.   1 root root          7 May 16  2019 python -> python2lrwxrwxrwx.   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

[[email protected] /]# python --versionPython 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

[[email protected] vagrant]# ll /usr/bin | grep pythonlrwxrwxrwx  1 root root         14 Feb  4 13:11 python -> /bin/python3.6lrwxrwxrwx  1 root root          9 Feb  4 13:08 python2 -> python2.7-rwxr-xr-x  1 root root       7216 Aug  7 09:52 python2.7lrwxrwxrwx  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

[[email protected] vagrant]# python --versionPython 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

解决方法请看https://www.cnblogs.com/gaoBlog/p/12262716.html

如何在centos7中安装python3