擅长:python、mysql、java
<blockquote>
<p>I don't know how to prevent the block from moving backward.</p>
</blockquote>
<p>实际上,您的块只向前移动<em>。如果将块的形状从<code>'square'</code>更改为<code>'arrow'</code>,您将看到它总是朝着它所面对的方向移动。如果你想以某种方式限制它,我们需要更好地描述你想要或不想要的运动类型</p>
<p>代码的简化版本,其中有一些小的调整:</p>
<pre><code>from turtle import Screen, Turtle
def moveu(angle):
turtle.setheading(angle)
turtle.forward(20)
screen = Screen()
screen.setup(400, 400)
turtle = Turtle()
turtle.shape('arrow')
turtle.speed('fastest')
turtle.penup()
screen.onkey(lambda: moveu(90), 'w')
screen.onkey(lambda: moveu(270), 's')
screen.onkey(lambda: moveu(180), 'a')
screen.onkey(lambda: moveu(0), 'd')
screen.listen()
screen.mainloop()
</code></pre>