#python This script is basic pygame code to move an object back and forth-ward with background

motorcycleCouple.py

'''============================================
For this tutorial, i'm gonna make a simple moving object
using pygame. This is based from the chimp tutorial on 
pygame website
editor: Son Pham 
date: 8/30/2018
files: https://goo.gl/7he7kG
python 3.7.0
=============================================='''
# import modules

import os, sys
import pygame
from pygame.locals import *

# load image and convert to surface object
def load_image(name):
	path = os.path.join('data', name)
	try:
		image = pygame.image.load(path)
	except pygame.error:
		print('Cannot Load Image', path)
	image = image.convert()
	return image, image.get_rect()

# sprite is a moving element 
class bike(pygame.sprite.Sprite):
	def __init__(self):
		pygame.sprite.Sprite.__init__(self)
		self.image, self.rect = load_image('motorcycleCouple.png')
		screen = pygame.display.get_surface()
		self.area = screen.get_rect()
		self.rect.topleft = 10, 150
		self.move = 4
		
	def update(self):
		self._run()
	# single under score is used for "internal use"
	#_run function will move a sprite from left to right
	# and flip
	def _run(self):
		newpos = self.rect.move(self.move,0)
		if self.rect.left < self.area.left or \
			self.rect.right > self.area.right:
			self.move = -self.move
			newpos = self.rect.move(self.move,0)
			self.image = pygame.transform.flip(self.image,1,0)
		self.rect = newpos

def main():
#initialize
	pygame.init()
	screen = pygame.display.set_mode((500,400))
	pygame.display.set_caption('Motorcycle Couple')
#create the background using background img
	background = pygame.image.load('data//background.png').convert()
#(optional) create the background using solid color
	# background = pygame.Surface(screen.get_size())
	# background = background.convert()
	# background.fill((128,128,128))
#put text on background
	font = pygame.font.Font(None, 36)
	text = font.render('Press ESC to exit', 1, (10,10,10))
	textpos = 280,10
	background.blit(text, textpos) #draw text on background
#display the background 
	screen.blit(background,(0,0))
#game object
	clock = pygame.time.Clock()
	Bike = bike()
	sprite = pygame.sprite.GroupSingle(Bike)
#main loop
	going = True
	while going:
		clock.tick(60)
		for event in pygame.event.get():
			if event.type == QUIT:
				going = False
			elif event.type == KEYDOWN and event.key == K_ESCAPE:
				going = False
		Bike.update()
		screen.blit(background,(0,0))
		sprite.draw(screen)
		pygame.display.flip()
	pygame.quit()
if __name__ == '__main__':
	main()