当吃豆人撞到墙的时候我遇到了麻烦。我输入了一个迷宫，用for循环画出了迷宫，吃豆人的动作也很好，但是当它撞到墙的时候我想让它停下来。
我怎么才能让它停下来，然后等待用户的输入来切换方向呢？我尝试的是使用一个变量来告诉它停下来，它会停下来，但它不会响应任何我会输入的键，让它再次移动

maze = [
"XXXXXXXXXXXXXXXXXXXXXXXXX",
"XP  XXXXXXXE           XX",
"X  XXXXXXX  XXXXXX  XXXXX",
"X       XX  XXXXXX  XXXXX",
"X       XX  XXX       EXX",
"XXXXXX  XX  XXX        XX",
"XXXXXX  XX  XXXXXX  XXXXX",
"XXXXXX  XX    XXXX  XXXXX",
"X  XXX        XXXX  XXXXX",
"X  XXX  XXXXXXXXXXXXXXXXX",
"X         XXXXXXXXXXXXXXX",
"X                XXXXXXXX",
"XXXXXXXXXXXX     XXXXX  X",
"XXXXXXXXXXXXXXX  XXXXX  X",
"XXX  XXXXXXXXXX         X",
"XXXE                    X",
"XXX         XXXXXXXXXXXXX",
"XXXXXXXXXX  XXXXXXXXXXXXX",
"XXXXXXXXXX              X",
"XX   XXXXX              X",
"XX   XXXXXXXXXXXXX  XXXXX",
"XX    YXXXXXXXXXXX  XXXXX",
"XX          XXXX        X",
"XXXXE                   X",
"XXXXXXXXXXXXXXXXXXXXXXXXX"
]

def move():

    if player.direction=="right":
        player.setx(player.xcor()+7)
    if player.direction=="left":
        player.setx(player.xcor()-7)
    if player.direction=="up":
        player.sety(player.ycor()+7)
    if player.direction=="down":
        player.sety(player.ycor()-7)
def right():
    player.direction="right"

def left():
    player.direction="left"

def up():
    player.direction="up"
    

def down():
    player.direction="down" 
 

def exit():
    turtle.bye()

screen=turtle.Screen()
screen.bgcolor("black")
screen.setup(900,900)
screen.tracer(n=0)
walllist=[]
x=-365
y=360

for r in maze:
    for h in r:
        if h=="X":
            wall=turtle.Turtle()
            wall.color("blue")
            wall.shapesize(1.43,1.43,1)
            wall.shape("square")
            wall.penup()
            wall.goto(x,y)
            walllist.append(wall)
        if h=="P":
            player=turtle.Turtle()
            player.speed(0)
            player.color("yellow")
            player.shape("circle")
            player.penup()
            player.direction="stop"
            player.goto(x,y)
        x+=30
    x=-365
    y-=30

screen.listen()
screen.onkey(right,"Right")
screen.onkey(up,"Up")
screen.onkey(down,"Down")
screen.onkey(left,"Left")
screen.onkey(exit,"Escape")

while True:
        move()
        screen.update()
        for wall in walllist:
            if player.distance(wall)<29:
              player.direction="stop"

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