run python code in sublime code example

Example 1: how do i run code in sublime text

for javascipt, command B doesn't seem to work for me.
It does work for python programmers though. To code, 
I use Processing.

Example 2: how to programm python 3 in sublime text

"cmd": ["python3", "-i", "-u", "$file"],     "file_regex": "^[ ]File \"(...?)\", line ([0-9]*)",     "selector": "source.python"