```"""
Show the proper way to organize a game using the a game class.

Sample Python/Pygame Programs
Simpson College Computer Science
http://simpson.edu/computer-science/

Explanation video: http://youtu.be/O4Y5KrNgP_c
"""

import pygame
import random

# --- Global constants ---
BLACK = (0, 0, 0)
WHITE = (255, 255, 255)
GREEN = (0, 255, 0)
RED = (255, 0, 0)

SCREEN_WIDTH = 700
SCREEN_HEIGHT = 500

# --- Classes ---

class Block(pygame.sprite.Sprite):
""" This class represents a simple block the player collects. """

def __init__(self):
""" Constructor, create the image of the block. """
super().__init__()
self.image = pygame.Surface([20, 20])
self.image.fill(BLACK)
self.rect = self.image.get_rect()

def reset_pos(self):
""" Called when the block is 'collected' or falls off
the screen. """
self.rect.y = random.randrange(-300, -20)
self.rect.x = random.randrange(SCREEN_WIDTH)

def update(self):
""" Automatically called when we need to move the block. """
self.rect.y += 1

if self.rect.y > SCREEN_HEIGHT + self.rect.height:
self.reset_pos()

class Player(pygame.sprite.Sprite):
""" This class represents the player. """
def __init__(self):
super().__init__()
self.image = pygame.Surface([20, 20])
self.image.fill(RED)
self.rect = self.image.get_rect()

def update(self):
""" Update the player location. """
pos = pygame.mouse.get_pos()
self.rect.x = pos
self.rect.y = pos

class Game(object):
""" This class represents an instance of the game. If we need to
reset the game we'd just need to create a new instance of this
class. """

def __init__(self):
""" Constructor. Create all our attributes and initialize
the game. """

self.score = 0
self.game_over = False

# Create sprite lists
self.block_list = pygame.sprite.Group()
self.all_sprites_list = pygame.sprite.Group()

# Create the block sprites
for i in range(50):
block = Block()

block.rect.x = random.randrange(SCREEN_WIDTH)
block.rect.y = random.randrange(-300, SCREEN_HEIGHT)

# Create the player
self.player = Player()

def process_events(self):
""" Process all of the events. Return a "True" if we need
to close the window. """

for event in pygame.event.get():
if event.type == pygame.QUIT:
return True
if event.type == pygame.MOUSEBUTTONDOWN:
if self.game_over:
self.__init__()

return False

def run_logic(self):
"""
This method is run each time through the frame. It
updates positions and checks for collisions.
"""
if not self.game_over:
# Move all the sprites
self.all_sprites_list.update()

# See if the player block has collided with anything.
blocks_hit_list = pygame.sprite.spritecollide(self.player, self.block_list, True)

# Check the list of collisions.
for block in blocks_hit_list:
self.score += 1
print(self.score)
# You can do something with "block" here.

if len(self.block_list) == 0:
self.game_over = True

def display_frame(self, screen):
""" Display everything to the screen for the game. """
screen.fill(WHITE)

if self.game_over:
# font = pygame.font.Font("Serif", 25)
font = pygame.font.SysFont("serif", 25)
text = font.render("Game Over, click to restart", True, BLACK)
center_x = (SCREEN_WIDTH // 2) - (text.get_width() // 2)
center_y = (SCREEN_HEIGHT // 2) - (text.get_height() // 2)
screen.blit(text, [center_x, center_y])

if not self.game_over:
self.all_sprites_list.draw(screen)

pygame.display.flip()

def main():
""" Main program function. """
# Initialize Pygame and set up the window
pygame.init()

size = [SCREEN_WIDTH, SCREEN_HEIGHT]
screen = pygame.display.set_mode(size)

pygame.display.set_caption("My Game")
pygame.mouse.set_visible(False)

# Create our objects and set the data
done = False
clock = pygame.time.Clock()

# Create an instance of the Game class
game = Game()

# Main game loop
while not done:

# Process events (keystrokes, mouse clicks, etc)
done = game.process_events()

# Update object positions, check for collisions
game.run_logic()

# Draw the current frame
game.display_frame(screen)

# Pause for the next frame
clock.tick(60)

# Close window and exit
pygame.quit()

# Call the main function, start up the game
if __name__ == "__main__":
main()

```
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