Question

我一次又一次地得到同样的错误。我想知道为什么每当我运行此代码时都会发生这种情况。错误是：

ValueError：无法将字符串转换为float：create

我正在制作一个有乌龟图形的行走者。这个程序运行几秒钟然后弹出一个错误并说python exe停止了。

import turtle
from threading import Thread

# Creating window
wn = turtle.Screen()
wn.setup(700,500)
wn.bgcolor("lightblue")
wn.title("johnny Walker")

# Creating circle
jw_head = turtle.Turtle()
jw_head.color("black")
jw_head.pensize(3)
jw_head.circle(30)
jw_head.hideturtle()

# Creating torso.
tor = turtle.Turtle()
tor.color("black")
tor.pensize(3)
tor.right(90)
tor.forward(150)
tor.hideturtle()

# Left hand.
left_hand = turtle.Turtle()
left_hand.color("black")
left_hand.speed(10)
left_hand.pensize(2)
left_hand.penup()
left_hand.setposition(0,-50)
left_hand.pendown()
left_hand.right(90)

# Right hand.
right_hand = turtle.Turtle()
right_hand.color("black")
right_hand.speed(10)
right_hand.pensize(2)
right_hand.penup()
right_hand.setposition(0,-45)
right_hand.pendown()
right_hand.right(90)


def l_hand():
    while True:
        angle = 1
        while angle < 90:
            left_hand.forward(100)
            left_hand.hideturtle()
            left_hand.clear()
            left_hand.penup()
            left_hand.setposition(0,-50)
            left_hand.pendown()
            left_hand.right(1)
            angle = angle + 1
        left_hand.left(90)

def r_hand():
    while True:
        angle1 = 1
        while angle1 < 90:
            right_hand.left(1)
            right_hand.forward(100)
            right_hand.hideturtle()
            right_hand.clear()
            right_hand.penup()
            right_hand.setposition(0,-45)
            right_hand.pendown()
            right_hand.left(1)
            angle1 = angle1 + 1
        right_hand.right(90)


p1 = Thread(target = l_hand)
p2 = Thread(target = r_hand)
p1.start()
p2.start()
p1.join()
p2.join()

Answer 1

运行代码时出现的错误是：

RuntimeError：主线程不在主循环中

我假设是由于在辅助线程上执行tkinter（它是turtle的基础）代码。您可以将线程与tkinter一起使用，但图形需要穿梭到主线程。

让我们重新开始使用turtle的内置ontimer()功能而不是线程。我不确定你的人物应该做什么，所以我做了一个简单的动画，他将手臂从直线向下移动到两侧，但速度不同：

from turtle import Turtle, Screen

# Creating window
wn = Screen()
wn.setup(700, 500)
wn.bgcolor('lightblue')
wn.title('johnny Walker')

# Creating circle
jw_head = Turtle(visible=False)
jw_head.speed('fastest')
jw_head.pensize(3)
jw_head.circle(30)

# Creating torso.
tor = Turtle(visible=False)
tor.speed('fastest')
tor.pensize(3)
tor.right(90)
tor.forward(150)

# Left hand.
left_hand = Turtle(visible=False)
left_hand.pensize(2)
left_hand.right(90)
left_hand.forward(50)
left_hand.forward(50)  # intentionally duplicated for undo()

# Right hand.
right_hand = Turtle(visible=False)
right_hand.pensize(2)
right_hand.right(90)
right_hand.forward(50)
right_hand.forward(50)  # intentionally duplicated for undo()

def l_hand():
    left_hand.undo()
    left_hand.left(1)
    left_hand.forward(50)
    wn.update()

    if left_hand.heading() < 359:
        wn.ontimer(l_hand, 100)

def r_hand():
    right_hand.undo()
    right_hand.right(1)
    right_hand.forward(50)
    wn.update()

    if right_hand.heading() > 179:
        wn.ontimer(r_hand, 50)

wn.tracer(False)

l_hand()
r_hand()

wn.mainloop()

如果你必须使用线程，这里有一个Multithreading With Python Turtle

的例子

使用Python Turtle和线程获取ValueError

1 个答案: