xenial apt存储库中python的最大版本是3.5.1-3
$ sudo apt-get upgrade python3
Reading package lists... Done
Building dependency tree
Reading state information... Done
python3 is already the newest version (3.5.1-3).
Calculating upgrade... Done
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
但我希望能够使用python3.6或更高版本。
如何通过apt升级它？