tkinter不允许一次运行2个线程

Question

我有一个游戏，我让世界向你移动，你可以同时跳跃。这两个功能分开工作，但它们在一起使用时不起作用。有时它会给我一个错误（ValueError：无法将字符串转换为float：expected）无法转换，有时字符会产生奇怪的抖动，有时它会同时发生，有时它会崩溃。这是我的代码

import Tkinter as tkinter
import thread
from time import sleep


def is_even(n):
    if n % 2 == 0:
        retVal = True
    else:
        retVal = False
    return retVal


class gameScreen:

    def move(self, event):
        d = self.getdir(event.keysym)
        self.canvas.move(self.char, d[0], d[1])
        self.canvas.update()
        if self.collision():
            self.canvas.move(self.char, -d[0], -d[1])

    def fall(self):
        speed = .01
        x = 0
        while not self.collision():
            self.canvas.move(self.char, 0, 1)
            self.canvas.update()
            sleep(speed)
            if x == 2:
                speed -= speed *.04
                x = 0
            else:
                x += 1
        self.canvas.move(self.char, 0, -1)

    def jump(self):
        j = 0
        from time import sleep
        jump = [6, 6, 6, 6, 4, 4, 2, 1, 0]

        for i in range(0, (len(jump)*2)):
            x = jump[j]
            self.canvas.move(self.char, 0, -x)
            if not  is_even(i):
                j +=1
            self.canvas.update()
            sleep(.05)
        self.fall()

    def getLast(self, lvl):
        x = 0
        for i in lvl:
            coords = self.canvas.coords(i)
            if x < coords[3]:
                x = coords[3]
                last = i
        return last

    def gameThread(self, event):
        thread.start_new_thread(self.gameStart, ())

    def gameStart(self, event=None):
        from time import sleep
        last = self.getLast(self.lvl1)
        coords = self.canvas.coords(last)

        while coords[2] > 0:
            print coords[2]
            for i in self.lvl1:
                self.canvas.move(i, -1, 0)
            coords = self.canvas.coords(last)
            self.canvas.update()
            sleep(.002)
            if not self.touchingGround(event):
                self.fall()

    def touchingGround(self, event = None):
        self.canvas.move(self.char, 0, 5)

        if self.collision():

            retVal = True
        else:
            retVal = False
        self.canvas.move(self.char, 0, -5)
        return retVal

    def onKey(self, event):
        if self.touchingGround(event):
            thread.start_new_thread(self.jump, ())

    def collision(self):
        coords = self.canvas.coords(self.char)
        collision =  len(self.canvas.find_overlapping(coords[0]-1, 
                                                      coords[1]-1,
                                                      coords[2]-1, 
                                                      coords[3]-1)) >=2
        return collision

    def getdir(self, s):
        direction = {"Left":[-5, 0], "Right":[5, 0]}
        try:
            retVal = direction[s]
        except KeyError:
            retVal =False
        return retVal

    def __init__(self, master):
        self.lvl1 = []
        self.objects = []
        self.master = master
        master.attributes("-fullscreen", True)
        master.title("Game")
        self.width=master.winfo_screenwidth()
        self.height=master.winfo_screenheight()
        self.canvas = tkinter.Canvas(master, width=self.width,
                                      height=self.height)
        self.canvas.pack(expand="YES",fill="both")
        self.objects.append(self.canvas.create_rectangle(0, self.height,
                                                         self.width,
                                                         self.height-100,
                                                         fill="grey"))
        self.lvl1.append(self.canvas.create_rectangle(self.width,
                                                         self.height-100,
                                                         self.width + 100,
                                                         self.height-150,
                                                         fill="grey"))
        self.objects.extend(self.lvl1)
        self.char = self.canvas.create_rectangle((self.width/2)-25, 
                                                 self.height- 100,
                                                 (self.width/2)+25, 
                                                 self.height-150, 
                                                 fill="red")
        self.x = 0
        self.y = 0
        master.bind("<Key-Up>", self.onKey)
        master.bind("<Return>", self.onKey)


def destroy(event):
    root.destroy()


root = tkinter.Tk()
my_gui = gameScreen(root)
root.bind("<Escape>", destroy)
root.mainloop()

我尝试添加像tadhg所说的后来，但它仍然只有时跳，并且大多数时候它完全跳跃，或者只是上升一到两个像素，然后再回落，然后重复该数量应该跳的时间。