我试着用python建立一个简单的海龟程序，我可以通过按下空格键来移动海龟，它一直在移动，直到我再次碰到空格键。我可以让他用太空出版社移动固定的距离，但不能让它继续下去。在

以下是我的工作：from turtle import *

# PUT YOUR CODE HERE

setup(800,600)

home()

pen_size = 2

color("blue")

title("Turtle")

speed("fastest")

drawdist= 25

current_state = penup

next_state = pendown

#Button Instructions

def move_up():

seth(90)

forward(drawdist)

def move_down():

seth(270)

forward(drawdist)

def move_left():

seth(180)

forward(drawdist)

def move_right():

seth(0)

forward(drawdist)

def space_bar():

seth(90)

forward(drawdist)

global current_state, next_state

next_state()

current_state, next_state = next_state, current_state

#Change Pen Color

def red():

color(