Pyglet hello world program

#!/usr/bin/env python3
import pyglet
from pyglet.window import key

class GameWindow(pyglet.window.Window):
  def __init__(self, *args, **kwargs):
    super().__init__(*args, **kwargs)
    self.pos=(200,200)
    self.angle=0
    self.movement=20
    imagetrain = pyglet.resource.image('locomotive.png')
    self.spritetrain = pyglet.sprite.Sprite(imagetrain)
    self.label = pyglet.text.Label('Hello, world',x=100,y=100,color=(100,100,255,255))
  def on_mouse_press(self, x, y, button, modifiers):
    pass
  def on_mouse_release(self, x, y, button, modifiers):
    pass
  def on_mouse_motion(self, x, y, dx, dy):
    pass
    #print("move mouse")
  def on_key_press(self, symbol, modifiers):
    #print("key was pressed",symbol)
    if symbol == key.A: self.angle-=10
    elif symbol == key.B: self.angle+=10
    elif symbol == key.ENTER: pass
    elif symbol == key.LEFT: 
      self.pos=(self.pos[0]-self.movement,self.pos[1])
    elif symbol == key.RIGHT: 
      self.pos=(self.pos[0]+self.movement,self.pos[1])
    elif symbol == key.UP: 
      self.pos=(self.pos[0],self.pos[1]+self.movement)
    elif symbol == key.DOWN: 
      self.pos=(self.pos[0],self.pos[1]-self.movement)
    self.spritetrain.update(x=self.pos[0],y=self.pos[1],rotation=self.angle)
  def update(self, dt):
    pass
    
  def on_draw(self):
    self.clear()  
    pyglet.gl.glClearColor(1,1,1,1)
    pyglet.graphics.draw(2,pyglet.gl.GL_LINES,
      ('v2i', (10, 15, 130, 135)),
      ('c3B', (100,100,255)*2), # one color per vertex
    )
    self.spritetrain.draw()
    self.label.draw() 

if __name__ == "__main__":
  window = GameWindow(600, 400, "pyglet",resizable=False)
  pyglet.clock.schedule_interval(window.update, 1/30.0)
  pyglet.app.run() 

Update

In a second version of the program, a dedicated class for the physics state was created. This simplified the programming a bit. The remaining commands for drawing the lines and the sprites will become easier, because once the code is written, it will draw all the elements to the screen.

Secondly, it was measured the exact cpu consumption. For 100 frames per second, the GUI app needs 15% of the totai CPU.

ps -p 31339 -o %cpu,%mem,cmd
%CPU %MEM CMD
15.1  1.3 python3 1.py

If the framerate is increased to 200 fps, the cpu consumption is 18%. It's important to know, that the only objects on the screen, are one sprite, one line and a small “hello world” text. It seems, that Python programs in general are running slow? No, that is not the case. Because a program written in high speed C++ with the SFML library has the same performance problems. It seems, that the requirements of updating the screen 200 times per second is too much for computers in general. No matter in which programming language the code was written.