如何在python中通过鼠标点击启动循环

Question

我正在努力寻找一种方法，让我的程序在用户单击原始图像后将图像更改为灰度。我认为我的问题出在花括号里。你知道吗

import image

img = image.Image("nature.jpg")
win = image.ImageWin(img.getWidth(), img.getHeight())
img.draw(win)
img.setDelay(1,15)

if {}:
    for row in range(img.getHeight()):
        for col in range(img.getWidth()):
            p = img.getPixel(col, row)

        aver = (p.getRed() + p.getGreen() + p.getBlue())/3

        newred = aver
        newgreen = aver
        newblue = aver

        newpixel = image.Pixel(newred, newgreen, newblue)

        img.setPixel(col, row, newpixel)

img.draw(win)