Python Turtle.Terminator even after using exitonclick()

问题

I have tried to make functions for turtle to make it extremely easy to draw shapes and the code looks like this

import turtle as t

def square():
     tw = t.Screen()
     for i in range(4):
          t.forward(100)
          t.right(90)
     tw.exitonclick()
def triangle():
     tw = t.Screen()
     for i in range(3):
          t.forward(100)
          t.right(120)
     tw.exitonclick()
def star():
     tw = t.Screen()
     for i in range(5):
          t.forward(150)
          t.right(144)
     tw.exitonclick()

when i run this code in shell a problem is fonud...

>>> square()
>>> triangle()
Traceback (most recent call last):
  File "<pyshell#1>", line 1, in <module>
    triangle()
  File "C:\Users\Manop\Desktop\XENON\turtleg.py", line 11, in triangle
    t.forward(100)
  File "<string>", line 5, in forward
turtle.Terminator
>>> star()
>>> square()
Traceback (most recent call last):
  File "<pyshell#3>", line 1, in <module>
    square()
  File "C:\Users\Manop\Desktop\XENON\turtleg.py", line 5, in square
    t.forward(100)
  File "<string>", line 5, in forward
turtle.Terminator
>>> 

can't get over what the problem is, because i even used exitonclick()

回答1:

I had the same error while I was working on a school project. After some research on the turtle library I have found a variable called TurtleScreen._RUNNING, if this variable is set to True a turtle window opens, if not you get the turtle.Terminator error. Every time you close a turtle screen, TurtleScreen._RUNNING is automatically set to True, if you want to avoid that, you can simply write this line of code TurtleScreen._RUNNING = True (of course you need to import turtle before).

回答2:

Your turtle program is structured incorrectly. You needn't do:

tw = t.Screen()
...
tw.exitonclick()

in every function. Screen() only needs to be called once; exitonclick() should only ever be called once. Try this restructuring:

import turtle as t

def square():
    for i in range(4):
        t.forward(100)
        t.right(90)

def triangle():
    for i in range(3):
        t.forward(100)
        t.right(120)

def star():
    for i in range(5):
        t.forward(150)
        t.right(144)

t.penup()
t.goto(150, 150)
t.pendown()
square()

t.penup()
t.goto(-150, 150)
t.pendown()
triangle()

t.penup()
t.goto(150, -150)
t.pendown()
star()

screen = t.Screen()
screen.exitonclick()

If you want to execute the code interactively, that's fine too. Just drop everything after the function definitions, load it into Python interactively and do:

>>> star()

or whatever you want to run. You don't need the call to Screen() and the exitonclick() doesn't make sense when working interactively.

回答3:

Let the method screen.exitonclick() be the last statement in your code without indenting it.

You use this method when your using a Python IDE such as Pycharm, Spyder etc.

I don't know if you have heard of the method screen.mainloop()

This method enables you see the output of your code when you run it in a Python IDE.

Without this method, your output would appear in a flash.

I rewrote your code and here's mine

from turtle import Turtle

t=Turtle()

def square():
    t.up()
    t.setpos(-50,-50)
    t.down()
    for i in range(4):
        t.forward(100)
        t.right(90)

def triangle():
    t.up()
    t.setpos(50,50)
    t.down()
    for i in range(3):
        t.forward(100)
        t.right(120)

def star():
    t.up()
    t.setpos(-200,100)
    t.down()
    for i in range(5):
        t.forward(150)
        t.right(144)

square()
triangle()
star()
t.screen.exitonclick()

Here's the output output of my program

You can also check this excellent guide in Python turtle

回答4:

When you interrupt the turtle drawing, it gets angry and produces "abnormal termination" error. Use a "running" flag to stop the process at any point:

from turtle import Turtle

t=Turtle()

def square():
    global running
    t.up()
    t.setpos(-50,-50)
    t.down()
    for i in range(4):
        if not running: break; # Check 'running' here
        t.forward(100)
        t.right(90)

def triangle():
    global running
    t.up()
    t.setpos(50,50)
    t.down()
    for i in range(3):
        if not running: break; # Check 'running' here
        t.forward(100)
        t.right(120)

def star():
    global running
    t.up()
    t.setpos(-200,100)
    t.down()
    for i in range(5):
        if not running: break; # Check 'running' here
        t.forward(150)
        t.right(144)

def stop(x,y): # x,y are dummy but they are requested
  global running
  running = False  # Disable running

t.screen.onclick(stop) # Set a function for 'running'

running = True  # Enable running

square()
triangle()
star()

I tested the above code. Termination was smooth at all times.

来源：https://stackoverflow.com/questions/45534458/python-turtle-terminator-even-after-using-exitonclick