使用onkey事件时我的Python海龟窗口崩溃

Question

My Python turtle window crashes when I try to move to the left. I am using the onkey in Python turtle graphics and when I try to use it my window completely crashes. Here is my code:

import turtle



wn = turtle.Screen()
wn.bgcolor("green")

crosshair = turtle.Turtle()
crosshair.shape("circle")

draw = turtle.Pen()
draw.color("brown")
draw.ht()

while True:

    def left():
        draw.st()
        draw.penup()
        draw.left(90)
        draw.forward(50)
        draw.pendown()
        draw.forward(100)
        draw.left(90)
        draw.forward(50)
        draw.right(90)
        draw.forward(100)
        draw.right(90)
        draw.forward(100)
        draw.right(90)
        draw.forward(100)
        draw.right(90)
        draw.forward(50)

    turtle.listen()
    turtle.onkey(left, "Left")

Answer 1

Your code isn't structured properly. You should not have an infinite while True: loop when using turtle. Instead, you should set up your event handlers, like onkey() , and turn control over to Tk's event loop using mainloop() . Python-wise, you don't need to define left() inside the loop, move it to the top level. Here's a rework that includes the above changes:

from turtle import Turtle, Screen

def left():
    draw.st()

    draw.penup()
    draw.left(90)
    draw.forward(50)
    draw.pendown()

    draw.forward(100)
    draw.left(90)

    draw.forward(50)
    draw.right(90)

    for _ in range(3):
        draw.forward(100)
        draw.right(90)

    draw.forward(50)

    draw.ht()

screen = Screen()
screen.bgcolor("green")

crosshair = Turtle("circle")

draw = Turtle(visible=False)
draw.color("brown")

screen.onkey(left, "Left")
screen.listen()

screen.mainloop()

Click on the window to make it active, then you can use your left arrow key to invoke the graphics: