本文使用的Ubuntu系统是WSL的Ubuntu-26.04版本，当前系统默认安装的Python版本是3.14。
本文主要通过Deadsnakes的PPA源来安装其他Python版本，并通过`update-alternatives` 命令来切换Python版本。
安装仓库并添加PPA
# 安装仓库
sudo apt install software-properties-common
# 添加ppa
sudo add-apt-repository ppa:deadsnakes/ppa
# 更新apt
sudo apt update安装Python
查看系统当前python版本：
$ python3 --version
Python 3.14.4安装Python3.13版本：
$ apt install python3.13
查看系统所有python版本：
$ ll /usr/bin/python*
lrwxrwxrwx 1 root root 10 Mar 21 17:46 /usr/bin/python3@ -> python3.14
-rwxr-xr-x 1 root root 6671680 Aug 6 19:06 /usr/bin/python3.13*
-rwxr-xr-x 1 root root 7477096 Apr 8 12:02 /usr/bin/python3.14*切换Python版本
向 “`update-alternatives“`添加需要管理的版本：
# 添加Python3.13版本
$ sudo update-alternatives --install /usr/bin/python3 python3 /usr/bin/python3.13 1
update-alternatives: using /usr/bin/python3.13 to provide /usr/bin/python3 (python3) in auto mode
# 添加Python3.14版本
$ sudo update-alternatives --install /usr/bin/python3 python3 /usr/bin/python3.14 2
update-alternatives: using /usr/bin/python3.14 to provide /usr/bin/python3 (python3) in auto mode
$ sudo update-alternatives --config python3
There are 2 choices for the alternative python3 (providing /usr/bin/python3).
Selection Path Priority Status
------------------------------------------------------------
* 0 /usr/bin/python3.14 2 auto mode
1 /usr/bin/python3.13 1 manual mode
2 /usr/bin/python3.14 2 manual mode
Press <enter> to keep the current choice[*], or type selection number: 1
update-alternatives: using /usr/bin/python3.13 to provide /usr/bin/python3 (python3) in manual mode
# 查看系统当前Python版本号
$ python3 --version
Python 3.13.15