text: from turtle import * 
  w = Screen()
  w.tracer(0,0)    #screen.delay(0)
  #w.delay(0)
  #w.setworldcoordinates(-1, -0.3, 3, 1.3)
  w.bgcolor("black")
  t = Turtle()
  
  A = 1
  B = 1
  C = 1
  
  POS_Y = -100
  POS_X = 100
  
  DIS_X = 70
  LOC_Y = -100
  
  class ColorTurtle(Turtle):
      def __init__(self, x, y , st ):
          Turtle.__init__(self)
          self.shape("square")
          self.shapesize(0.5,1)
          
          self.color("white")
  
          self.pu()
          self.goto(x,LOC_Y)
          self.pd()
          self.sety(y*2 + LOC_Y)
          self.write(st)
          self.pu()
          self.sety(y + LOC_Y)
          self.ondrag(self.shift)
  
      def shift(self, x, y):
          self.sety(max(LOC_Y,min(y,2*POS_Y + LOC_Y)))
          updoot()
          w.update()
  
  def updoot():
      global A , B , C
      A = A_mod.ycor()
      B = B_mod.ycor()
      C = C_mod.ycor()
      T = [ A , B , C ]
      print(T)
      w.update()
  def main():
      
      global A_mod , B_mod , C_mod
      A_mod = ColorTurtle(POS_X - DIS_X , POS_Y , "A" )
      B_mod = ColorTurtle(POS_X         , POS_Y , "B" )
      C_mod = ColorTurtle(POS_X + DIS_X , POS_Y , "C" )
      updoot()
  
  
  main()
  