How to get rid of Python Launcher icon every time a script runs?

Using Sublime Text 2 or Atom (maybe other editors too), when running a simple plotting script in python, the Python Launcher icon (the rocket) pops up every time I run the code, and so the icons add up in the dock (see image), and I have to close them individually. Is there any configuration to avoid this behavior?

Edit: With Sublime Text, for instance, cmd-B is the default shortcut I use to run a script. I have not found this issue addressed in Atom’s or ST’s documentation (neither in stackexchange).