使用Ubuntu 16.04.7时，我试图将python3.8作为我的默认python版本。我遵循了这里给出的说明，但最终标准python版本没有改变。每当我运行时
python -V
输出总是
Python 3.7.9
以下是sudo update-alternatives --config python3:的输出
There are 2 choices for the alternative python3 (providing /usr/bin/python3).
Selection Path Priority Status
------------------------------------------------------------
* 0 /usr/bin/python3.8 2 auto mode
1 /usr/bin/python3.7 1 manual mode
2 /usr/bin/python3.8 2 manual mode
Press <enter> to keep the current choice[*], or type selection number:
当我选择"0"时，我得到错误：
update-alternatives: warning: forcing reinstallation of alternative /usr/bin/python3.8 because link group python3 is broken
谷歌上唯一的热门是另一个没有答案的SO条目！
那么我该如何解决这个问题呢？
此外，这里是ls -l /usr/bin/python*:的输出
lrwxrwxrwx 1 root root 18 Oct 17 2019 /usr/bin/python -> /usr/bin/python2.7
lrwxrwxrwx 1 root root 9 Nov 24 2017 /usr/bin/python2 -> python2.7
-rwxr-xr-x 1 root root 3488528 Jul 21 19:57 /usr/bin/python2.7
lrwxrwxrwx 1 root root 33 Jul 21 19:57 /usr/bin/python2.7-config -> x86_64-linux-gnu-python2.7-config
lrwxrwxrwx 1 root root 16 Nov 24 2017 /usr/bin/python2-config -> python2.7-config
-rwxr-xr-x 1 root root 306 Oct 24 2015 /usr/bin/python2-futurize
-rwxr-xr-x 1 root root 310 Oct 24 2015 /usr/bin/python2-pasteurize
lrwxrwxrwx 1 root root 25 Oct 5 08:59 /usr/bin/python3 -> /etc/alternatives/python3
-rwxr-xr-x 2 root root 4456208 Jul 19 22:14 /usr/bin/python3.5
lrwxrwxrwx 1 root root 33 Jul 19 22:14 /usr/bin/python3.5-config -> x86_64-linux-gnu-python3.5-config
-rwxr-xr-x 2 root root 4456208 Jul 19 22:14 /usr/bin/python3.5m
lrwxrwxrwx 1 root root 34 Jul 19 22:14 /usr/bin/python3.5m-config -> x86_64-linux-gnu-python3.5m-config
-rwxr-xr-x 2 root root 5074632 Aug 18 09:35 /usr/bin/python3.7
-rwxr-xr-x 2 root root 5074632 Aug 18 09:35 /usr/bin/python3.7m
-rwxr-xr-x 1 root root 5391992 Sep 26 00:51 /usr/bin/python3.8
lrwxrwxrwx 1 root root 16 Mar 23 2016 /usr/bin/python3-config -> python3.5-config
lrwxrwxrwx 1 root root 10 Mar 23 2016 /usr/bin/python3m -> python3.5m
lrwxrwxrwx 1 root root 17 Mar 23 2016 /usr/bin/python3m-config -> python3.5m-config
lrwxrwxrwx 1 root root 16 Nov 24 2017 /usr/bin/python-config -> python2.7-config
lrwxrwxrwx 1 root root 58 Mar 25 2016 /usr/bin/pythontex -> ../share/texlive/texmf-dist/scripts/pythontex/pythontex.py
-rwxr-xr-x 1 root root 306 Mar 25 2016 /usr/bin/pythontex3
我为python定义了一个别名！这就是为什么传统逻辑在这里不适用！
我通过这种方式将py3.8设置为默认值
export py=`which python`
sudo rm $py
export py38=`which python3.8`
sudo ln -s $py38 $py