If anyone has the patience to take a look at my first python snake game, I'd be very grateful for any feedback. I am fairly new to programming and Python, but am looking to improve so any constructive feedback is appreciated.
import Tkinter
import time
import random
UP = u'\uf700'
DOWN = u'\uf701'
LEFT = u"\uf702"
RIGHT = u'\uf703'
TIMESTEP = 50
WIDTH = 300
HEIGHT = 300
colours = ['blue','red','pink','yellow','cyan','magenta','green']
class game(object):
def __init__(self):
self.window = Tkinter.Tk()
self.canvas = Tkinter.Canvas(self.window, width = WIDTH, height = HEIGHT)
self.canvas.pack()
self.leader = Rect(self.canvas,50,50,60,60,'red',10,0)
self.rect2 = Rect(self.canvas,40,50,50,60,'blue',10,0)
self.test1 = Rect(self.canvas,100,100,110,110,'pink',0,0)
self.followers = [self.rect2,self.test1,Rect(self.canvas,200,200,210,210,'yellow',0,0)]
def moveit(self):
# moves the leader and the followers follow!
prevpos = (self.leader.coords()[0],self.leader.coords()[1])
self.leader.move(self.leader.getvel()[0],self.leader.getvel()[1])
for rect in self.followers:
x = (rect.coords()[0],rect.coords()[1])
self.moveto(rect,prevpos)
prevpos = x
self.eatapple()
self.selfcollision()
self.throughwalls()
self.window.after(TIMESTEP,self.moveit)
def moveto(self,box1,pos):
#moves box1 to pos
box1.move(pos[0]-box1.coords()[0],pos[1]-box1.coords()[1])
def makeapple(self):
#This randomly puts an apple on the canvas
x1 = random.randrange(0,WIDTH,10)
y1 = random.randrange(0,HEIGHT,10)
self.apple = Rect(self.canvas,x1,y1,x1+10,y1+10, 'purple',0,0)
def eatapple(self):
#This check for eating apple, if eaten, creates new apple and grows the snake
if self.leader.coords() == self.apple.coords():
self.canvas.delete(self.apple.id)
self.makeapple()
self.grow()
def grow(self):
# grows the snake by appending a rectangle to the followers list
x1 = self.followers[-1].coords()[0]
y1 = self.followers[-1].coords()[1]
x2 = self.followers[-1].coords()[2]
y2 = self.followers[-1].coords()[3]
self.followers.append(Rect(self.canvas,x1,y1,x2,y2,colours[random.randint(0,len(colours)-1)],0,0))
def selfcollision(self):
# This will check for collision with itself
for follower in self.followers:
if self.leader.coords() == follower.coords():
print "You lose!"
self.window.destroy()
def throughwalls(self):
# This will put the snake on the klein bottle geometry!
x1,y1,x2,y2 = self.leader.coords()
if x1>=WIDTH:
self.moveto(self.leader,(0,HEIGHT-y1))
if x1<0:
self.moveto(self.leader,(WIDTH,HEIGHT-y1))
if y1>= HEIGHT:
self.moveto(self.leader,(x1,0))
if y1< 0:
self.moveto(self.leader,(x1,HEIGHT))
def keyup(self,event):
if self.leader.velocity != (0,10):
self.leader.velocity=(0,-10)
#print "UP!"
def keydown(self,event):
if self.leader.velocity != (0,-10):
self.leader.velocity = (0,10)
#print "DOWN!"
def keyright(self,event):
if self.leader.velocity != (-10,0):
self.leader.velocity = (10,0)
def keyleft(self,event):
if self.leader.velocity != (10,0):
self.leader.velocity = (-10,0)
def mainloop(self):
self.window.bind("<Key-Up>",self.keyup)
self.window.bind("<Key-Down>",self.keydown)
self.window.bind("<Key-Left>",self.keyleft)
self.window.bind("<Key-Right>",self.keyright)
self.makeapple()
self.moveit()
self.window.mainloop()
class Rect(object):
def __init__(self,canvas,x1,y1,x2,y2,color,vx,vy):
self.canvas = canvas
self.velocity = vx,vy
self.id = self.canvas.create_rectangle(x1,y1,x2,y2,fill = color)
def getvel(self):
return self.velocity
def coords(self):
return self.canvas.coords(self.id)
#self.root = Tkin
def move(self,vx,vy):
self.canvas.move(self.id,vx,vy)
canvas = game()
canvas.mainloop()
while True:
ans=raw_input("Another game? (y/n) ")
if ans== 'n':
break
elif ans == 'y':
canvas = game()
canvas.mainloop()
else:
print "What was that?"
Also, this snake lives on the Klein bottle, as opposed to the usual Torus snake.
One specific question:
Games such as this require a loop that moves the blocks around the canvas. One can achieve this with a while loop, however I read somewhere that this was not advised as there is already a mainloop() running. Instead, one should use Tkinter's "after" function. Can anyone explain why this is favourable?
