dt_movement.py

import pygame as pg


class Square(object):
    def __init__(self, center_point, size):
        self.image = pg.Surface(size)
        self.image.fill(pg.Color("dodgerblue"))
        self.rect = self.image.get_rect(center=center_point)
        self.pos = self.rect.center
        self.x_velocity = 0

    def update(self, dt, keys):
        self.x_velocity = 0
        if keys[pg.K_LEFT]:
            self.x_velocity = -.1
        elif keys[pg.K_RIGHT]:
            self.x_velocity = .1
        self.pos = self.pos[0] + (self.x_velocity * dt), self.pos[1]
        self.rect.center = self.pos

    def draw(self, surface):
        surface.blit(self.image, self.rect)


class App(object):
    def __init__(self):
        self.screen = pg.display.set_mode((1280, 720))
        self.clock = pg.time.Clock()
        self.fps = 60
        self.done = False
        self.square = Square((640, 360), (100, 100))
        self.caption = "FPS: {:8} CLOCKED_FPS: {}"
        
    def event_loop(self, dt):
        for event in pg.event.get():
            if event.type == pg.QUIT:
                self.done = True

    def update(self, dt):
        keys = pg.key.get_pressed()
        if keys[pg.K_UP]:
            self.fps += 1
        elif keys[pg.K_DOWN]:
            self.fps = max(10, self.fps - 1)
        self.square.update(dt, keys)

    def draw(self):
        self.screen.fill(pg.Color("gray5"))
        self.square.draw(self.screen)

    def run(self):
        while not self.done:
            dt = self.clock.tick(self.fps)
            self.event_loop(dt)
            self.update(dt)
            self.draw()
            caption = self.caption.format(self.fps, self.clock.get_fps())
            pg.display.set_caption(caption)
            pg.display.update()


if __name__ == "__main__":
    app = App()
    app.run()
    pg.quit()