comp_key_press.py

import sys
import random
import pygame as pg


SCREEN_SIZE = (500, 500)
BACKGROUND = pg.Color("slategray")
TEXT_COLOR = pg.Color("tomato")
POST_DELAY = 300
FPS = 60

KEYS = (pg.K_LEFT, pg.K_RIGHT, pg.K_UP, pg.K_DOWN)


class App(object):
    def __init__(self):
        self.screen = pg.display.get_surface()
        self.screen_rect = self.screen.get_rect()
        self.clock = pg.time.Clock()
        self.done = False
        self.hit_key = ""
        self.timer = 0.0
        self.message = None
        self.rect = None

    def event_loop(self):
        for event in pg.event.get():
            if event.type == pg.QUIT:
                self.done = True
            elif event.type == pg.KEYDOWN:
                self.render_key(pg.key.name(event.key))
                
    def update(self, dt):
        self.timer += dt
        while self.timer >= POST_DELAY:
            self.timer -= POST_DELAY
            key_event = pg.event.Event(pg.KEYDOWN, key=random.choice(KEYS))
            pg.event.post(key_event)
            
    def render_key(self, pressed):
        if pressed != self.hit_key:
            self.message = FONT.render(self.hit_key, True, TEXT_COLOR)
            self.hit_key = pressed
            self.rect = self.message.get_rect(center=self.screen_rect.center)

    def render(self):
        self.screen.fill(BACKGROUND)
        if self.message:
            self.screen.blit(self.message, self.rect)
        pg.display.update()

    def main_loop(self):
        dt = 0.0
        self.clock.tick()
        while not self.done:
            self.event_loop()
            self.update(dt)
            self.render()
            dt = self.clock.tick(FPS)


def main():
    global FONT
    pg.init()
    pg.display.set_mode(SCREEN_SIZE)
    FONT = pg.font.Font(None, 65)
    App().main_loop()
    pg.quit()
    sys.exit()


if __name__ == "__main__":
    main()