Problem with pygame not switching the mouse image

[metulburr]

I need to be able to switch the image inside a Def depending on the mouse being press or released.

Then all you need to do is check if the mouse is down. This modification of my example shows the mouse cursor when not held down, and the image when is held down. 

import pygame as pg

screen = pg.display.set_mode((800,600))
screen_rect = screen.get_rect()
done = False
cursor_img = 'curs.jpg'
cursor = pg.image.load(cursor_img).convert()
cursor_rect = cursor.get_rect()
is_cursor = False

while not done:
    screen.fill((255,0,0))
    for event in pg.event.get():
        if event.type == pg.QUIT:
            done = True
    if pg.mouse.get_pressed()[0]:
        is_cursor = True
        pg.mouse.set_visible(False)
    else:
        is_cursor = False
        pg.mouse.set_visible(True)

    cursor_rect.center = pg.mouse.get_pos()
    if is_cursor:
        screen.blit(cursor, cursor_rect)
    pg.display.update()