Raspberry Pi A, User Manual, Page: 282 / 314

P A R T V
A P P E N D I X E S
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THE FOLLOWING RECIPES provide the program code for Example 3 and Example 4 in
Chapter 12, “An Introduction to Python”, and a sample solution for the combined input-output
program suggested in Chapter 14, “The GPIO Port”. Each recipe is also available for download
from the Raspberry Pi User Guide website at
www.wiley.com/go/raspberrypiuser
guide2e
. If you’re typing the code in by hand, look out for the
↵
symbol: this indicates that
the line is wrapped due to space constraints in the book. If you see the symbol at the end of a
line, don’t press Enter until you reach the end of a line that doesn’t have a symbol present.
Raspberry Snake (Chapter 12, Example 3)
#!/usr/bin/env python
# Raspberry Snake
# Written by Gareth Halfacree for the Raspberry Pi User Guide
import pygame, sys, time, random
from pygame.locals import *
pygame.init()
fpsClock = pygame.time.Clock()
playSurface = pygame.display.set_mode((640, 480))
pygame.display.set_caption(‘Raspberry Snake’)
redColour = pygame.Color(255, 0, 0)
blackColour = pygame.Color(0, 0, 0)
whiteColour = pygame.Color(255, 255, 255)
greyColour = pygame.Color(150, 150, 150)
snakePosition = [100,100]
snakeSegments = [[100,100],[80,100],[60,100]]
raspberryPosition = [300,300]
raspberrySpawned = 1
direction = ‘right’
changeDirection = direction
def gameOver():
gameOverFont = pygame.font.Font(‘freesansbold.ttf’, 72)
gameOverSurf = gameOverFont.render
↵
(‘Game Over’, True, greyColour)
gameOverRect = gameOverSurf.get_rect()
gameOverRect.midtop = (320, 10)
playSurface.blit(gameOverSurf, gameOverRect)
pygame.display.flip()