Python 关闭屏幕上的乌龟错误 - 来自如何像计算机科学家一样思考的代码：与 Python 一起学习 3

Question

当我运行这个代码

import turtle
import time

def show_poly():
    try:
        win = turtle.Screen()
        tess = turtle.Turtle()
        n = int(input("How many sides do you want in your polygon?"))
        angle = 360 / n
        for i in range(n):
            tess.forward(10)
            tess.left(angle)
        time.sleep(3)
    finally:
        win.bye()

show_poly()
show_poly()
show_poly()

我得到的第一个调用比我得到的这个错误更正常

Traceback (most recent call last): File "/home/turte.py", line 19, in show_poly()

File "/home/turte.py", line 8, in show_poly tess = turtle.Turtle()

File "/usr/lib/python3.5/turtle.py", line 3816, in init visible=visible)

File "/usr/lib/python3.5/turtle.py", line 2557, in init self._update()

File "/usr/lib/python3.5/turtle.py", line 2660, in _update self._update_data()

File "/usr/lib/python3.5/turtle.py", line 2646, in _update_data self.screen._incrementudc()

File "/usr/lib/python3.5/turtle.py", line 1292, in _incrementudc

raise Terminator turtle.Terminator

如果我理解这个问题，即使关闭最后一个屏幕，我也无法创建新屏幕。我运行python3.5

Answer 1

turtle.Screen() 返回的对象旨在成为单例，因此您的代码正在积极对抗模块设计。根据 the docs，您应该在应用程序中使用 RawTurtle 的实例。

import turtle
import time
import tkinter as tk


def show_poly():
    try:
        n = int(input("How many sides do you want in your polygon?"))
        angle = 360 / n
        root = tk.Tk()
        canvas = turtle.ScrolledCanvas(root)
        canvas.pack(expand=True, fill='both')
        tess = turtle.RawTurtle(canvas)
        for i in range(n):
            tess.forward(10)
            tess.left(angle)
        time.sleep(3)
    finally:
        root.destroy()


show_poly()
show_poly()
show_poly()

Answer 2

另一种方法是在 turtle 中工作，并尽可能避免使用 tkinter。在下面的解决方案中，我们不是销毁 window 并创建一个新的，而是简单地清除它并重新绘制：

from turtle import Turtle, Screen
from time import sleep

def show_poly(turtle):
    n = 0

    while n < 3:
        try:
            n = int(input("How many sides do you want in your polygon? "))
        except ValueError:
            pass

    angle = 360 / n

    for _ in range(n):
        turtle.forward(50)
        turtle.left(angle)

    sleep(3)
    turtle.clear()

window = Screen()

tess = Turtle()

show_poly(tess)
show_poly(tess)
show_poly(tess)

window.bye()

这也应该与 Python 2.7 和 Python 3

兼容

Python 关闭屏幕上的乌龟错误 - 来自如何像计算机科学家一样思考的代码：与 Python 一起学习 3

Python turtle error on closing screen - code from How to Think Like a Computer Scientist: Learning with Python 3

python

turtle-graphics

python-3.5