Snake Game written in Python with PyGame

Snek.py

   
import time, pygame
from random import randint

#for some reason you have to start modules? whatever.
pygame.init()

#can't make the numbers unequal? TODO: FIX THIS
blocks_square = 25

#height and width based on num blocks
blocks_height = blocks_square
blocks_width = blocks_square

#block width and padding in pixels
block_size = 15
padding = 1

#canvas size calculation
c_height = (blocks_height * (block_size + padding)) + padding
c_width = (blocks_width * (block_size + padding)) + padding

#speed settings
speed = 60 # -infinity to +133
full_speed = 0.05
crawl_speed = .2

#Wait time computation
speed = float(speed)
speed_width = -1 * (full_speed - crawl_speed)
#print "speed_width: ",speed_width
speed_coef = speed / 100
#print "speed coefficient:",speed_coef
speed_dif = speed_width * speed_coef
#print "speed difference:",speed_dif
wait_time = crawl_speed - speed_dif

screen = pygame.display.set_mode((c_width, c_height))


def reset_bg(color=(255,255,255)):
	screen.fill(color)

def make_grid(height,width,block_size,padding):
	grid = [[None for x in range(blocks_width)] for y in range(blocks_height)]
	for h_pos in range(blocks_height):
		y_pos = (h_pos * (block_size + padding)) + padding
		top = y_pos
		for w_pos in range(blocks_height):
			x_pos = (w_pos * (block_size + padding)) + padding
			left = x_pos
			grid[h_pos][w_pos] = pygame.Rect(left,top,block_size,block_size)
	return grid

# pygame.Rect(left,top,width,height)
def draw_grid(grid,screen):
	bg_block_color = (0,255,0)
	for row in grid: #h_pos
		for rect_obj in row:
			pygame.draw.rect(screen,bg_block_color,rect_obj)

def make_goal(grid, snek):
	max_x = len(grid[0]) - 2
	max_y = len(grid) - 2
	while True:
		x = randint(1,max_x)
		y = randint(1,max_y)
		if((x,y) in snek):
			#print "cannot make goal there, in snek!"
			continue
		else:
			#print "new goal!:",x,",",y
			return (x,y)

def move_snek(grid,snek,dir_key_code,old_key_code):
	#print "snek recieved in move_snek:",snek
	#get the pop for when the snake eats an egg
	head_val = snek[len(snek)-1]
	pop = snek.pop(0)
	if dir_key_code == 273: #up
		new_val = (head_val[0]-1,head_val[1])
	elif dir_key_code == 274: #down
		new_val = (head_val[0]+1,head_val[1])
	elif dir_key_code == 276: #left
		new_val = (head_val[0],head_val[1]-1)
	elif dir_key_code == 275: #right
		new_val = (head_val[0],head_val[1]+1)
	else:
		#print "NOT A VALID dir_key_code in move_snek():",dir_key_code
		return False,False
	#make sure the new value is still on the grid
	on_grid = False
	if 0 <= new_val[0] <= len(grid)-1:
		if 0 <= new_val[1] <= len(grid[0])-1:
			on_grid = True
	#make sure the new value isn't already part of the snek
	if on_grid and (new_val not in snek):
		snek.append(new_val)
		#print "new snek in move_snek:",snek
		return snek,pop
	else:
		return False

def draw_snek(snek,grid,screen):
	snek_color = (0,128,0)
	#print "SNEK IN draw_snek:",snek
	for tup in snek:
		pygame.draw.rect(screen,snek_color,grid[tup[0]][tup[1]])

def draw_goal(goal,grid,screen):
	goal_color = (176,0,0)
	pygame.draw.rect(screen,goal_color,grid[goal[0]][goal[1]])




#make a menu screen, press up button to start, down to cancel?
while True:
	reset_bg()
	pygame.display.update()
	pygame.font.init()
	#make font settings
	font_size = 50
	font_height = (c_height/2)-font_size
	font_width = (c_width/2)-font_size
	sub_font_height = (c_height/2)
	sub_font_width = (c_width/2)-(font_size*3.25)
	my_font = pygame.font.SysFont(pygame.font.get_default_font(),50)
	sub_font = pygame.font.SysFont(pygame.font.get_default_font(),25)
	#make the title surface with font
	text_surface = my_font.render('Snek',False,(0,0,0));
	sub_text_surface = my_font.render('press space to start',False,(0,0,0));
	screen.blit(text_surface,(font_width,font_height))
	screen.blit(sub_text_surface,(sub_font_width,sub_font_height))
	#update with menu font
	pygame.display.update()

	got_space = False
	while True:
		events = pygame.event.get()
		for event in events:
			if event.type == pygame.KEYDOWN and event.key == 32:
				got_space = True
				break
		if got_space:
			break



	#make grid for this to go on
	grid = make_grid(blocks_height,blocks_width,block_size,padding)
	#snek is list where pop() and append() drive movement
	snek = [make_goal(grid,[])]
	#make random goal (snake position excluded)
	goal = make_goal(grid,snek)
	#print "goal x:",goal[0],",y:",goal[1]

	#set up the initial window before starting with an initial direction
	reset_bg()
	draw_snek(snek,grid,screen)
	draw_goal(goal,grid,screen)
	pygame.display.update()

	#get an initial direction from the user
	# up == key 273, down == 274, left == 276, right == 275
	got_direction = False
	while True:
		events = pygame.event.get()
		for event in events:
			if event.type == pygame.KEYDOWN and 276 >= event.key >= 273:
				dir_key_code = event.key
				got_direction = True
				break
		if got_direction:
			break

	#have to know the last direction so we can ignore the opposite key
	old_key_code = dir_key_code

	#have to instantiate goal_hit
	goal_hit = False
	done = False

	#while true keep game running
	while True:
		#hesitate here for input
		time.sleep(wait_time)
		#check direction change
		old_key_code = dir_key_code
		events = pygame.event.get()
		for event in events:
			if event.type == pygame.KEYDOWN and 276 >= event.key >= 273:
				dir_key_code = event.key
				break
			if event.type == pygame.QUIT:
				done = True
		if done == True:
			break
		#reset the background
		reset_bg()
		#draw the grid on
		#draw_grid(grid,screen)

		#move the snek in direction (make sure to hold onto pop() value)
		try:
			snek,pop = move_snek(grid,snek,dir_key_code,old_key_code)
		except:
			break

		#if snek out of bounds or eats self (as rpsnt by False, end game
		if snek == False:
			time.sleep(10)
			break
		#if goal in snake,
		if goal in snek:
			if goal_hit == False:
				# add 1 to end of snake (pop() value from earlier)
				snek = [pop] + snek[:]
				#  set a new goal
				goal = make_goal(grid,snek)
				goal_hit = True
		elif goal_hit == True:
			goal_hit = False
		#draw snek
		draw_snek(snek,grid,screen)
		#draw goal
		draw_goal(goal,grid,screen)
		#render, bro.
		pygame.display.update()