Upgrading python 3.5 to python 3.6 - Ubuntu

Question

This is the first time I am working with python. I am using ubuntu 16.04 system. I am trying to change default python 3.5 to python 3.6 I am following this link to achieve this.

But I am getting the following error when I fire the command :

sudo update-alternatives --config python3

Error : bash: /usr/bin/python3: Too many levels of symbolic links

Please refer the screenshot of the steps which I followed and the commands that are executed. I have first fired update and upgrade command.

I am not able to understand root cause of the issue, since I am new to python and its environment.

Thank you

Solution 1

Following command worked for me:

sudo apt-get -f upgrade python3.6

Solution 2

follow below steps:-

sudo add-apt-repository ppa:jonathonf/python-3.6

sudo apt-get update

sudo apt-get install python3.6

sudo update-alternatives --install /usr/bin/python3 python3 /usr/bin/python3.6

Solution 3

Answers here seem a bit out of date, mainly because the PPA no longer exists. This is what worked for me (relying on one of the links posted in some of the question comments, among others):

sudo add-apt-repository ppa:deadsnakes/ppa
sudo apt-get update
sudo apt-get install python3.6

(now we have both versions, need to switch the "toggle")

sudo update-alternatives --install /usr/bin/python3 python3 /usr/bin/python3.6 0

Mind the trailing 0.

Comments

[Harsha Biyani]

askubuntu.com/questions/865554/…

[Bartłomiej]

There is some circular symlink. See unix.stackexchange.com/q/141436/226403

[Shivkumar Mallesappa]

@Bartłomiej : Thank you for your response. I understand that there is some issue with symlink , but I am not able to understand which symlink is causing this issue , which one I should use and which one I should remove. Could you please throw some light on this for me to understand this in a bit detail.

[Bartłomiej]

@Shivkumar Mallesappa, Sorry, I do not know full solution, that is why I just put a comment, not an answer, hoping that it might be useful.

[michael_heath]

The link in the question has a update at the bottom of the article about removing and creating the symlink that causes issue. update-alternatives is possibly finding an invalid link so you may need to manually use rm and ln to fix.

[Kashif]

check this maybe helpfull for you stackoverflow.com/questions/21690009/…

[Miron]

Cannot add PPA: 'ppa:~jonathonf/ubuntu/python-3.6'. ERROR: '~jonathonf' user or team does not exist. This is all I see.

[Mohit Khandelwal]

Got following error after running this command : E: Unable to locate package python3.6