Ubuntu中切换默认python版本

在ubuntu中切换默认python版本

有时候需要在默认python中使用不通版本的python，这里对于该操作做一下记录

当前版本（Ubuntu 18.04）

python3

结果是

Python 3.6.5 (default, Apr  1 2018, 05:46:30)
[GCC 7.3.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>>

可以看到，当前版本是3.6， 我们希望输入python3时使用的python版本为3.8

安装新版本python

sudo apt-get install python3.8

查看python3.8

python3.8

结果是

Python 3.6.5 (default, Apr  1 2018, 05:46:30)
[GCC 7.3.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>>

切换默认版本

查看系统下的python

whereis python

结果

python: /usr/bin/python3.6 /usr/bin/python2.7 /usr/bin/python3.6m /usr/bin/python3.8 /usr/lib/python3.6 /usr/lib/python2.7 /usr/lib/python3.8 /etc/python3.6 /etc/python2.7 /etc/python3.8 /usr/local/lib/python3.6 /usr/local/lib/python2.7 /usr/local/lib/python3.8

添加python3.8版本到python3

update-alternatives --install /usr/bin/python3 python3 /usr/bin/python3.8 1

输出

update-alternatives: using /usr/bin/python3.8 to provide /usr/bin/python3 (python3) in auto mode

添加python3.6版本到python3

update-alternatives --install /usr/bin/python3 python3 /usr/bin/python3.6
2

输出

update-alternatives: using /usr/bin/python3.6 to provide /usr/bin/python3 (python3) in auto mode

查看python3中所有版本

update-alternatives --list python3

切换版本

update-alternatives --config python

按照提示切换版本

输入2之后，回车，测试版本切换是否成功

python3

输出

Python 3.8.0 (default, Dec  9 2021, 17:53:27)
[GCC 8.4.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>>

切换成功！！！