问暂停time.time流

EN

import sys
import pygame as pg


pg.init()
screen = pg.display.set_mode((640, 480))
clock = pg.time.Clock()
font = pg.font.Font(None, 30)
timer = 0
dt = 0
paused = False
running = True

while running:
    for event in pg.event.get():
        if event.type == pg.QUIT:
            running = False
        elif event.type == pg.KEYDOWN:
            paused = not paused
            # This is needed to discard the time that
            # passed while the game was paused.
            clock.tick()

    if not paused:
        timer += dt  # Add delta time to increase the timer.

        screen.fill((30, 30, 30))
        txt = font.render(str(round(timer, 2)), True, (90, 120, 40))
        screen.blit(txt, (20, 20))

        pg.display.flip()
        dt = clock.tick(30) / 1000  # dt = time in seconds since last tick.

pg.quit()
sys.exit()