如何避免出现“当前绘制对象”错误？

Question

I want to write a Python program which will shows a letter in a graphics window. If I click the right side of the window, the text needs to turn red and if I click the left side it needs to turn green. It needs to work for at least five times. I write down following which change color only two times and then gives me "graphics.GraphicsError: Object currently drawn". Any idea how to fix this problem?

from graphics import *

def main():
    win= GraphWin("Name",400,400)
    win.setCoords(0.0,0.0,4.0,4.0)
    win.setBackground("white")
    p=Text(Point(2.0,2.0),'B')
    p.setSize(36)
    for i in  range(0,6): 
        c=win.getMouse()
        s=c.getX()

       if s>=2 :

           p.setTextColor("Red")
       else:
           p.setTextColor("Green")

       p.draw(win)
 main()

I am new to this. I used zelle graphics module to do this

Answer 1

The problem is the position of the p.draw(win) call as @korefn suggests. However, this change makes 'B' visible before the first click unlike your original code. I've included some commented out code in my rework below that will make the 'B' the same color as the background until clicked:

from graphics import *

def main():
    win = GraphWin('Mouse Test', 400, 400)
    win.setCoords(0.0, 0.0, 4.0, 4.0)

    anchorPoint = Point(2.0, 2.0)

    text = Text(anchorPoint, 'B')
    text.setSize(36)  # maximum legal size
    # text.setTextColor('white')  # optional initial invisibility
    text.draw(win)

    for _ in range(6):
        point = win.getMouse()

        if point.getX() >= anchorPoint.getX():
            text.setTextColor('red')
        else:
            text.setTextColor('green')

    win.close()

main()