import turtle

import time

import random

delay = 0.1

c = input("Do you want to play(u) or watch the algorithm (a)play ? ")

# Set up the screen

win = turtle.Screen()

win.title("SNAKE")

win.bgcolor("black")

win.setup(width=650, height=450)

box = turtle.Turtle()

box.speed(0)

box.shape("square")

box.color("red")

box.penup()

box.hideturtle()

box.goto(300, -200)

box.pendown()

box.goto(300, 200)

box.goto(-300, 200)

box.goto(-300, -200)

box.goto(300, -200)

box.penup()

win.tracer(0)

# Turns off the screen updates

# Snake head

head = turtle.Turtle()

head.speed(0)

turtle.register_shape("sq", ((0,0), (0,20), (20,20),(20,0)))

head.shape("sq")

head.color("green")

head.penup()

head.goto(-300,-180)

head.direction = "stop"

# Snake food

food = turtle.Turtle()

food.speed(0)

food.shape("sq")

food.color("blue")

food.penup()

food.goto(0,100)

segments = []

# Functions

def go_up():

if head.direction != "down":

head.direction = "up"

def go_down():

if head.direction != "up":

head.direction = "down"

def go_left():

if head.direction != "right":

head.direction = "left"

def go_right():

if head.direction != "left":

head.direction = "right"

def go_fast():

global delay

delay=delay/2

def go_slow():

global delay

delay=delay*2

def move():

head.setx(x + 20)

def foodp():

food.goto(x,y)

# Keyboard bindings

win.listen()

#user playing controls

if c=='u':

win.onkeypress(go_up, "Up")

win.onkeypress(go_down, "Down")

win.onkeypress(go_left, "Left")

win.onkeypress(go_right, "Right")

# Main game loop

while True:

win.update()

if c=='a' or c=='u':

# Check for a collision with the border

if head.xcor()>280 or head.xcor()<-300 or head.ycor()>200 or head.ycor()<-180:

time.sleep(2)

if c=='a':

time.sleep(20)

head.goto(-300,-10)

head.direction = "stop"

# Hide the segments

for segment in segments:

segment.goto(15000, 15000)

# Clear the segments list

segments.clear()

# Reset the delay

delay = 0.1

# Check for a collision with the food

if head.distance(food) < 20:

foodp()

# Move the food to a random spot

# Add a segment

new_segment = turtle.Turtle()

new_segment.speed(0)

new_segment.shape("sq")

new_segment.color("green")

new_segment.penup()

segments.append(new_segment)

# Shorten the delay

if c=='u':

delay -= 0.001

# Move the end segments first in reverse order

for index in range(len(segments)-1, 0, -1):

x = segments[index-1].xcor()

y = segments[index-1].ycor()

segments[index].goto(x, y)

# Move segment 0 to where the head is

if len(segments) > 0:

x = head.xcor()

y = head.ycor()

segments[0].goto(x,y)

move()

# Check for head collision with the body segments

for segment in segments:

if segment.distance(head) < 0:

time.sleep(2)

if c=='a':

time.sleep(20)

head.goto(-300,-180)

head.direction = "stop"

# Hide the segments

for segment in segments:

segment.goto(1000, 1000)

# Clear the segments list

segments.clear()

# Reset the delay

delay = 0.1

if c=='a':

win.onkeypress(go_fast, "a")

win.onkeypress(go_slow, "s")

if head.ycor()>200:

go_right()

move()

go_down()

move()

if head.xcor()<-280:

go_up()

elif head.ycor()==-180 and head.xcor()!=280 and head.direction!='left':

go_right()

move()

go_up()

move()

elif head.ycor()==-180:

go_left()

time.sleep(delay)

win.mainloop()