# Simple Snake Game in Python 3 for Beginners
 
import turtle
import time
import random
 
delay = 0.1
 
# Score
score = 0
high_score = 0
 
# Set up the screen
wn = turtle.Screen()
wn.title("Snake Game by @TokyoEdTech")
wn.bgcolor("green")
wn.setup(width=600, height=600)
wn.tracer(0)  # Turns off the screen updates
 
# Snake head
head = turtle.Turtle()
head.speed(0)
head.shape("square")
head.color("black")
head.penup()
head.goto(0, 0)
head.direction = "stop"
 
# Snake food
food = turtle.Turtle()
food.speed(0)
food.shape("circle")
food.color("red")
food.penup()
food.goto(0, 100)
 
segments = []
 
# Pen
pen = turtle.Turtle()
pen.speed(0)
pen.shape("square")
pen.color("white")
pen.penup()
pen.hideturtle()
pen.goto(0, 260)
pen.write("Score: 0  High Score: 0", align="center",
          font=("Courier", 24, "normal"))
 
# 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 move():
    if head.direction == "up":
        y = head.ycor()
        head.sety(y + 20)
 
    if head.direction == "down":
        y = head.ycor()
        head.sety(y - 20)
 
    if head.direction == "left":
        x = head.xcor()
        head.setx(x - 20)
 
    if head.direction == "right":
        x = head.xcor()
        head.setx(x + 20)
 
 
# Keyboard bindings
wn.listen()
wn.onkeypress(go_up, "Up")
wn.onkeypress(go_down, "Down")
wn.onkeypress(go_left, "Left")
wn.onkeypress(go_right, "Right")
 
# Main game loop
while True:
    wn.update()
 
    # Check for a collision with the border
    if head.xcor() > 290 or head.xcor() < -290 or head.ycor() > 290 or head.ycor() < -290:
        time.sleep(1)
        head.goto(0, 0)
        head.direction = "stop"
 
        # Hide the segments
        for segment in segments:
            segment.goto(1000, 1000)
 
        # Clear the segments list
        segments.clear()
 
        # Reset the score
        score = 0
 
        # Reset the delay
        delay = 0.1
 
        pen.clear()
        pen.write("Score: {}  High Score: {}".format(score, high_score),
                  align="center", font=("Courier", 24, "normal"))
 
    # Check for a collision with the food
    if head.distance(food) < 20:
        # Move the food to a random spot
        x = random.randint(-290, 290)
        y = random.randint(-290, 290)
        food.goto(x, y)
 
        # Add a segment
        new_segment = turtle.Turtle()
        new_segment.speed(0)
        new_segment.shape("square")
        new_segment.color("grey")
        new_segment.penup()
        segments.append(new_segment)
 
        # Shorten the delay
        delay -= 0.001
 
        # Increase the score
        score += 10
 
        if score > high_score:
            high_score = score
 
        pen.clear()
        pen.write("Score: {}  High Score: {}".format(score, high_score),
                  align="center", font=("Courier", 24, "normal"))
 
    # 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) < 20:
            time.sleep(1)
            head.goto(0, 0)
            head.direction = "stop"
 
            # Hide the segments
            for segment in segments:
                segment.goto(1000, 1000)
 
            # Clear the segments list
            segments.clear()
 
            # Reset the score
            score = 0
 
            # Reset the delay
            delay = 0.1
 
            # Update the score display
            pen.clear()
            pen.write("Score: {}  High Score: {}".format(
                score, high_score), align="center", font=("Courier", 24, "normal"))
 
    time.sleep(delay)
 
wn.mainloop()