def create_block():
""" Creates an apple to be eaten """
global BLOCK
posx = SEG_SIZE random.randint(1, (WIDTH-SEG_SIZE) / SEG_SIZE)
posy = SEG_SIZE random.randint(1, (HEIGHT-SEG_SIZE) / SEG_SIZE)
BLOCK = c.create_oval(posx, posy,
posx+SEG_SIZE, posy+SEG_SIZE,
fill="red")
def main():
""" Handles game process """
global IN_GAME
if IN_GAME:
s.move()
head_coords = c.coords(s.segments[-1].instance)
x1, y1, x2, y2 = head_coords
Check for collision with gamefield edges
if x2 > WIDTH or x1 < 0 or y1 < 0 or y2 > HEIGHT:
IN_GAME = False
# Eating apples
elif head_coords == c.coords(BLOCK):
s.add_segment()
c.delete(BLOCK)
create_block()
# Self-eating
else:
for index in range(len(s.segments)-1):
if head_coords == c.coords(s.segments[index].instance):
IN_GAME = False
root.after(100, main)
# Not IN_GAME -> stop game and print message
else:
set_state(restart_text, 'normal')
set_state(game_over_text, 'normal')
class Segment(object):
""" Single snake segment """
def init(self, x, y):
self.instance = c.create_rectangle(x, y,
x+SEG_SIZE, y+SEG_SIZE,
fill="white")
class Snake(object):
""" Simple Snake class """
def init(self, segments):
self.segments = segments
possible moves
self.mapping = {"Down": (0, 1), "Right": (1, 0),
"Up": (0, -1), "Left": (-1, 0)}
# initial movement direction
self.vector = self.mapping["Right"]
def move(self):
""" Moves the snake with the specified vector"""
for index in range(len(self.segments)-1):
segment = self.segments[index].instance
x1, y1, x2, y2 = c.coords(self.segments[index+1].instance)
c.coords(segment, x1, y1, x2, y2)
x1, y1, x2, y2 = c.coords(self.segments[-2].instance)
c.coords(self.segments[-1].instance,
x1+self.vector[0]*SEG_SIZE, y1+self.vector[1]*SEG_SIZE,
x2+self.vector[0]*SEG_SIZE, y2+self.vector[1]*SEG_SIZE)
def add_segment(self):
""" Adds segment to the snake """
last_seg = c.coords(self.segments[0].instance)
x = last_seg[2] - SEG_SIZE
y = last_seg[3] - SEG_SIZE
self.segments.insert(0, Segment(x, y))
def change_direction(self, event):
""" Changes direction of snake """
if event.keysym in self.mapping:
self.vector = self.mapping[event.keysym]
def reset_snake(self):
for segment in self.segments:
c.delete(segment.instance)
from tkinter import Tk, Canvas import random
Globals
WIDTH = 800 HEIGHT = 600 SEG_SIZE = 20 IN_GAME = True
Helper functions
def create_block(): """ Creates an apple to be eaten """ global BLOCK posx = SEG_SIZE random.randint(1, (WIDTH-SEG_SIZE) / SEG_SIZE) posy = SEG_SIZE random.randint(1, (HEIGHT-SEG_SIZE) / SEG_SIZE) BLOCK = c.create_oval(posx, posy, posx+SEG_SIZE, posy+SEG_SIZE, fill="red")
def main(): """ Handles game process """ global IN_GAME if IN_GAME: s.move() head_coords = c.coords(s.segments[-1].instance) x1, y1, x2, y2 = head_coords
Check for collision with gamefield edges
class Segment(object): """ Single snake segment """ def init(self, x, y): self.instance = c.create_rectangle(x, y, x+SEG_SIZE, y+SEG_SIZE, fill="white")
class Snake(object): """ Simple Snake class """ def init(self, segments): self.segments = segments
possible moves
def set_state(item, state): c.itemconfigure(item, state=state)
def clicked(event): global IN_GAME s.reset_snake() IN_GAME = True c.delete(BLOCK) c.itemconfigure(restart_text, state='hidden') c.itemconfigure(game_over_text, state='hidden') start_game()
def start_game(): global s create_block() s = create_snake()
Reaction on keypress
def create_snake():
creating segments and snake
Setting up window
root = Tk() root.title("PythonicWay Snake")
c = Canvas(root, width=WIDTH, height=HEIGHT, bg="#003300") c.grid()
catch keypressing
c.focus_set() game_over_text = c.create_text(WIDTH/2, HEIGHT/2, text="GAME OVER!", font='Arial 20', fill='red', state='hidden') restart_text = c.create_text(WIDTH/2, HEIGHT-HEIGHT/3, font='Arial 30', fill='white', text="Click here to restart", state='hidden') c.tag_bind(restart_text, "", clicked)
start_game()
root.mainloop()