import pygame, random, sys, time
from pygame import *
from pygame.locals import *

# define main variables
Scr_width = 700
Scr_height = 500
mousePos = None
mouseBot = None
Circs = []
index = None
y = 0
def start(Scr_width, Scr_height):
    global scr
    init()
    scr = display.set_mode((Scr_width, Scr_height))

start(Scr_width, Scr_height)
while True:
    for ev in event.get():
        if ev.type == QUIT:
            pygame.quit()
            sys.exit()
        elif ev.type == KEYDOWN:
            if ev.key == K_ESCAPE:
                pygame.quit()
                sys.exit()
        elif ev.type == MOUSEBUTTONDOWN:
            mousePos = ev.pos
            mouseBot = ev.button
            if mouseBot == 1:
                Circs.append(mousePos)
            elif mouseBot == 3:
                Circs = []
                scr.fill((0, 0, 0))
                display.update()
        pygame.event.clear()
    print(' length is ', len(Circs))
    if len(Circs) == 1:
        draw.circle(scr, (0, 240, 0), Circs[0], 10)
    if len(Circs) > 1:
        for x in (0, len(Circs)):
            draw.circle(scr, (0, 240, 0), Circs[x], 10)
            pass
    display.update()