1.概述本文记录了在Ubuntu16.04上将python升级到3.8版本并配置为系统默认python3的过程。在Ubuntu16.04中，python3默认版本为3.5：$python3-VPython3.5.2本文以在Ubuntu16.04中安装为例，该方法同样适用于Ubuntu18.04。2.通过Apt安装UbuntuPython3.8还没有包含在官方的apt库中，所以使用deadsnakesPPA库来安装。2.1.安装依赖项$sudoaptupdate$sudoaptinstallsoftware-properties-common2.2。添加deadsnakesPPA源$sudoadd-apt-repositoryppa:deadsnakes/ppaPress[ENTER]继续或Ctrl-c取消添加它.2.3。安装python3.8$sudoaptinstallpython3.8$python3.8-VPython3.8.23。配置python3.8为系统默认python3。修改默认的python3会导致打不开Terminal等各种问题。解决方案参见Ubuntu16。04TLS3.1无法打开终端的解决方法。将每个版本的python添加到update-alternatives$whichpython3.8/usr/bin/python3.8$sudoupdate-alternatives--install/usr/bin/python3python3/usr/bin/python3.81$whichpython3.5/usr/bin/python3.5$sudoupdate-alternatives--install/usr/bin/python3python3/usr/bin/python3.523.2。配置python3默认指向python3.8$sudoupdate-alternatives--configpython3可选的python3有2个选择（提供/usr/bin/python3）。选择路径优先级状态----------------------------------------------------------*0/usr/bin/python3.52自动omode1/usr/bin/python3.52manualmode2/usr/bin/python3.81manualmodePress
