[PyGame] boilerplate

[Windspar]

Here how I handle it
scene.py

import pygame_sdl2 as pygame

# internal working of my scene.
class Scene(object):
    # scene loading before seen
    def has_focus(self): pass
    # scene dumping before switching
    def lost_focus(self): pass
    # scene drawing
    def blit(self, surface): pass
    # scene time updates
    def update(self, tick): pass
    # scene events
    def event(self, event): pass

# scene switching
class Handler(object):
    # for passing variables without passing object
    scenes = {}
    fps = None
    running = False
    set_scene = None
    size = None

    # set caption and window
    def __init__(self, caption, size, flags=0, depth=0):
        Handler.size = size
        self.current_scene = Scene()
        self.screen = pygame.display.set_mode(size, flags, depth)
        pygame.display.set_caption(caption)
        self.clock = pygame.time.Clock()

    # main loop
    def loop(self, start_scene=None, fps=60):
        Handler.fps = fps
        Handler.running = True
        Handler.set_scene = start_scene

        while Handler.running:
            if Handler.set_scene:
                self.current_scene.lost_focus()
                self.current_scene = Handler.scenes[Handler.set_scene]
                self.current_scene.has_focus()
                Handler.set_scene = None

            for event in pygame.event.get():
                self.current_scene.event(event)

            self.current_scene.blit(self.screen)
            tick = pygame.time.get_ticks()
            self.current_scene.update(tick)

            pygame.display.flip()
            self.clock.tick(Handler.fps)

# function for quick access to variables.
def add_scene(scene_name, scene):
    Handler.scenes[scene_name] = scene

def set_scene(scene_name):
    Handler.set_scene = scene_name

def quit_scene():
    Handler.running = False

def get_screensize():
    return Handler.size

def set_fps(fps):
    Handler.fps = fps

I just import my boilerplate
example.py

import pygame_sdl2 as pygame
import scene

pygame.init()

class Example(scene.Scene):
    def __init__(self):
        scene.Scene.__init__(self)
        # scene variables here

    def blit(self, surface):
        surface.fill((0,0,120))
        # draw code here

    def event(self, event):
        # event code here
        if event.type == pygame.QUIT:
            scene.quit_scene()

if __name__ == '__main__':
    handler = scene.Handler('Example', (800,600))
    E = Example()
    scene.add_scene('Example', E)
    handler.loop('Example')

    pygame.quit()