I am new to ubuntu and I wanted to shift my version to Python 3.4.1.

So I ran the command:

$ sudo update-alternatives --config python

update-alternatives: error: no alternatives for python

But then I try to run command:

$ sudo apt-get install python3.4

Reading package lists... Done

Building dependency tree       

Reading state information... Done

python3.4 is already the newest version.

0 upgraded, 0 newly installed, 0 to remove and 14 not upgraded.

I don't know how to switch between the versions. Please help.