Another simple Python game: Memory

This week's assignment is a simple and straight forward Memory game. You play with a set of cards facedown and you are allowed to flip and view two cards in one turn and if they both match, they remain opened. If they don't they go back to facedown mode and you use your memory to match the cards. You can play it here:

UPDATE: I was doing peer evaluation for this and I found one implementation which is better than mine. It uses classes. Check it here:

__author__ = 'RK Kuppala'
# implementation of card game - Memory
import simplegui
import random

num_list = []
exposed = []
state = 0
first_pick = 0
second_pick = 0
moves = 0

# helper function to initialize globals
def init():
    global num_list, exposed, moves
    moves = 0
    num_list = [i%8 for i in range(16)]
    random.shuffle(num_list)
    exposed = [False for i in range(16)]
    pass


# define event handlers
def mouseclick(pos):
    global state, first_pick, second_pick, moves
    this_pick = int(pos[0] / 50)
    if state == 0:
        first_pick = this_pick
        exposed[first_pick] = True
        state = 1
        moves += 1
    elif state == 1:
        if not exposed[this_pick]:
            second_pick = int(pos[0] / 50)
            exposed[second_pick] = True
            state = 2
            moves += 1
    elif state == 2:
        if not exposed[this_pick]:
            if num_list[first_pick] == num_list[second_pick]:
                pass
            else:
                exposed[first_pick] = False
                exposed[second_pick] = False
            first_pick = this_pick
            exposed[first_pick] = True
            state = 1
            moves += 1
    l.set_text("Moves = " + str(moves))
    pass


# cards are logically 50x100 pixels in size
def draw(canvas):
    offset = 50
    hor_pos = -25
    for i in range(len(num_list)):
        hor_pos += offset
        canvas.draw_text(str(num_list[i]), [hor_pos, 50], 30, "White")
    exposed_pos = -50
    for i in exposed:
        exposed_pos += offset
        if not i:
            canvas.draw_polygon([(exposed_pos, 0), (exposed_pos + 50, 0), (exposed_pos + 50, 100), (exposed_pos + 0, 100)], 10, "White", "Orange")

# create frame and add a button and labels
frame = simplegui.create_frame("Memory", 800, 100)
frame.add_button("Restart", init)
l=frame.add_label("Moves = 0")

# initialize global variables
init()

# register event handlers
frame.set_mouseclick_handler(mouseclick)
frame.set_draw_handler(draw)

# get things rolling
frame.start()