ubuntu安装python3.6为啥装不上

我跟着别人写的教程安装python3.6，但是我就是装不上，也不知道咋解决，所以这是啥情况呢
我的

x@x-virtual-machine:~$ sudo add-apt-repository ppa:jonathonf/python-3.6 
Cannot add PPA: 'ppa:~jonathonf/ubuntu/python-3.6'.
The user named '~jonathonf' has no PPA named 'ubuntu/python-3.6'
Please choose from the following available PPAs:
 * 'ansible':  Ansible
 * 'atslang':  ATS2 programming language
 * 'backports':  Backport collection
 * 'barrier':  Barrier
 * 'bazel':  Bazel
 * 'byobu':  Byobu
 * 'calibre':  Calibre
 * 'clementine':  Clementine
 * 'compton':  Compton
 * 'cpan':  Packaged CPAN modules
 * 'debhelper':  debhelper
 * 'debhelper-10':  debhelper 10
 * 'debhelper-11':  debhelper 11
 * 'debhelper-12':  debhelper 12
 * 'debhelper-trusty':  debhelper for trusty

别人的

将命令改为
sudo add-apt-repository ppa:deadsnakes/ppa