Python onkey 不停止循环

Question

def startgame():
    start.state = False
    print start.state


def restart():
    end.state = False
    start.state = True
    print game.state, end.state


s.listen()

s.onkey(startgame, "Return")

s.onkey(restart, 'r')

# This Loop stops when you hit Enter

while start.state:
    start.enter()
s.reset()

# I tried repeating it here but it doesn't work
while end.state:
    end.enter()
s.reset()
game.state = 'playing'

Both loops are nested in a main while loop but the second one is nested in another while loop (If that helps) so it would look something like this

while True:
    while start.state:
        start.flash()
    s.reset()
    while True:

        # main game code here

        while end.state:
            end.flash()
        s.reset()
        game.state = 'playing'
        break

I simply want it to show the end screen and have 'Press r to play again' flash on screen until the player hits r and then it should restart the game and go back to the start screen. The end.state variable wont update during the while loop, but start.state does during its while loop.

Answer 1

Your drawn out (in time) while loops have no place in an event-driven environment like turtle. In general, we need to control everything with events, specifically timer events . Let's rewrite your code as a state machine. (Since I don't have your object classes, entities like start.state become globals like start_state in my example code.)

from turtle import Screen, Turtle

start_state = True
end_state = False

def start_game():
    global start_state

    start_state = False

def end_game():
    global end_state

    if not start_state:
        end_state = True

def restart_game():
    global end_state, start_state

    end_state = False
    start_state = True

def flash(text):
    turtle.clear()
    turtle.write(text, align="center", font=('Arial', 24, 'bold'))

    color = turtle.pencolor()
    turtle.pencolor(turtle.fillcolor())
    turtle.fillcolor(color)

def game_states():

    if start_state:
        flash("Start")
    elif end_state:
        flash("End")
    else:
        flash("Playing")

    screen.ontimer(game_states, 500)

screen = Screen()

turtle = Turtle()
turtle.hideturtle()
turtle.fillcolor(screen.bgcolor())

screen.onkey(start_game, 'Return')
screen.onkey(restart_game, 'r')
screen.onkey(end_game, 'e')
screen.listen()

game_states()

screen.mainloop()

The state machine rules are:

Start via <Return> -> Playing
Playing via <e> -> End and via <r> -> Start
End via <r> -> Start