ubuntu安装python 3.5

Question

How can I easily install python 3.5 on ubuntu? In this article https://askubuntu.com/questions/682869/install-python-3-5-on-vivid-using-apt-get write what im must run next comand

sudo add-apt-repository ppa:fkrull/deadsnakes
sudo apt-get update
sudo apt-get install python3.5

But im run

  sudo add-apt-repository ppa:fkrull/deadsnakes

and its output next error

unable to execute /usr/bin/add-apt-repository: No such file or directory

Answer 1

It comes by default when you run the current release :

edd@max:~$ python --version
Python 2.7.11+
edd@max:~$ python3.5 --version
Python 3.5.1+
edd@max:~$

So available but not yet the default python engine. That is using

edd@max:~$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description:    Ubuntu 16.04 LTS
Release:        16.04
Codename:       xenial
edd@max:~$ 

Answer 2

Is software-properties-common installed? You can check by running apt-cache search software-properties-common On my 14.04 it shows:

$ apt-cache policy software-properties-common 
software-properties-common:
  Installed: 0.92.37.7
  Candidate: 0.92.37.7
  Version table:
 *** 0.92.37.7 0
        500 http://gb.archive.ubuntu.com/ubuntu/ trusty-updates/main amd64 Packages
        100 /var/lib/dpkg/status
     0.92.36 0
        500 http://gb.archive.ubuntu.com/ubuntu/ trusty/main amd64 Packages

If it isn't installed then try installing it using apt. I'm not sure why it wouldn't be installed though as it seems to be fairly core.

Also make sure that the directory /etc/apt/sources.list.d exists on your system.