Display text on 3d viewport [duplicate]

Question

Is there a way to display text on the 3d viewport. (not text objects) After running a script I would like to display instructions on what to do next.

I have tried this scrip and it works well.. is there a way to use a script to get rid of it?

import bpy
import blf

class DrawingClass:
    def __init__(self, context, prop):
        self.prop = prop
        self.handle = bpy.types.SpaceView3D.draw_handler_add(
                   self.draw_text_callback,(context,),
                   'WINDOW', 'POST_PIXEL')

    def draw_text_callback(self, context):
        font_id = 0  # XXX, need to find out how best to get this.

        # draw some text
        blf.position(font_id, 15, 50, 0)
        blf.size(font_id, 20, 72)
        blf.draw(font_id, "%s %s" % (context.scene.name, self.prop))

    def remove_handle(self):
         bpy.types.SpaceView3D.draw_handler_remove(self.handle, 'WINDOW')

context = bpy.context             
dns = bpy.app.driver_namespace
dns["dc"] = DrawingClass(context, "Draw This On Screen")