How to install python3 on Linux

Install python3

$ sudo apt-get install python3-pip python3-venv python3 <enter>

Make an isolated environment
$ mkdir environment <enter>
$ cd environment <enter>
$ python3 -m venv my_env <enter>

where my_env is the isolated environment
$ ls my_env <enter>

to display the created folders

Activate the isolated environment
$ source ~/environment/my_env/bin/activate <enter>

This will be the resulting prompt
(my_env) patrick@rm01:~/environments$

Create a small program in the isolated environment
nano hello.py <enter>
print ("Hello World")

Save the file.

python hello.py <enter>

Deactivate the isolated environment

deactivate to deactivate the isolated environment and return to home directory.