I think you are referring to your IDE, the editor you are using to write your code. If this is the case, that would depend on your editor, which one are you using?
If you are using the built-in editor IDLE, then what you are looking to do is not an available option.
If you are trying to do this within your own code using wxPython (as SexySaxMan suggested), please provide an example of your code so we can get a better idea of what you are trying to do.