Installing Python 3.5 On Linux Mint 17.3

I am very new to linux and want to use python as it is the language I am learning at school. I have looked online and checked my current version is 2.7 which is no good to me as I

Solution 1:

The default python3 in Mint17.3 is python3.4, and you can use ppa:fkrull to install python3.5.

sudo add-apt-repository ppa:deadsnakes/ppa
sudo apt-getupdate; 
sudo apt-get install python3.5

Solution 2:

First of all, you can install as many Python versions as you wish, that won't do anything bad for your OS. But changing the default Python interpreter may be not so good.

Secondly, you can use any IDE (such as PyCharm) for coding or just use your favorite text editor and just run python your_file.py in the terminal.