def __init__(self, xspan, yspan):

self.state = set()

self.xspan, self.yspan = xspan, yspan

def set(self, x, y):

key = (x, y)

self.state.add(key)

def flip_state(self, x, y):

# if the cell is alive -> dead

# if the cell is dead -> alive

key = (x, y)

if key in self.state:

self.state.remove(key)

else:

self.state.add(key)

def clear_board(self):

self.state.clear()

def step(self):

post_step_state = set()

for i in range(self.xspan):

# creates a range of the x-adjacent cells

x_range = range(i-1, i+2)

for j in range(self.yspan):

s = 0

live = ((i, j) in self.state)

# creates a range of the y-adjacent cells

for y_pos in range(j-1, j+2):

for x_pos in x_range:

if (x_pos, y_pos) in self.state:

s += 1

# removes the cell in question from the count of adjacent cells

# subtracts either a 1 or 0 depending on the state of the cell

s -= live

if s == 3:

# A cell is born

post_step_state.add((i, j))

elif s == 2 and live:

# The cell remains alive

post_step_state.add((i, j))

# All other cases result in death

self.state = post_step_state

def draw(self, x, y):

turtle.penup()

key = (x, y)

if key in self.state:

turtle.setpos(x*SIZE, y*SIZE)

turtle.color('red')

# perhaps make new cells 'green' for their first generation

turtle.pendown()

# sets the direction of the turtle 0 degrees (->)

turtle.setheading(0)

turtle.begin_fill()

# traces out the square in a counter clockwise path

for i in range(4):

turtle.forward(SIZE-1)

turtle.left(90)

turtle.end_fill()

def display(self):

turtle.clear()

# draws all live cells from grid.state

for i in range(self.xspan):

for j in range(self.yspan):

self.draw(i, j)

turtle.update()

# prints out the keys of the live cells

def print_keys(self):

for key in self.state:

print(key)

# inputs the coordinates for a Glider at the top left corner of the grid

def glider(self):

points = [(3.0, 56.0), (2.0, 56.0), (1.0, 56.0), (3.0, 57.0), (2.0, 58.0)]

for key in points:

self.state.add(key)

# inputs the coordinates for a Garden of Eden on the grid

def garden(self):

points = [(24.0, 30.0),(52.0, 35.0),(25.0, 31.0),(53.0, 34.0),(26.0, 28.0),

(33.0, 36.0),(47.0, 28.0),(52.0, 28.0),(41.0, 36.0),(32.0, 31.0),

(36.0, 34.0),(42.0, 35.0),(54.0, 30.0),(34.0, 29.0),(39.0, 32.0),

(26.0, 32.0),(49.0, 32.0),(28.0, 35.0),(23.0, 35.0),(41.0, 29.0),

(22.0, 28.0),(31.0, 35.0),(35.0, 36.0),(34.0, 36.0),(27.0, 28.0),

(32.0, 28.0),(28.0, 31.0),(43.0, 36.0),(42.0, 36.0),(49.0, 28.0),

(34.0, 30.0),(30.0, 29.0),(35.0, 31.0),(51.0, 34.0),(40.0, 29.0),

(32.0, 35.0),(37.0, 29.0),(42.0, 31.0),(40.0, 35.0),(35.0, 35.0),

(43.0, 30.0),(23.0, 28.0),(41.0, 34.0),(48.0, 30.0),(36.0, 36.0),

(28.0, 28.0),(24.0, 36.0),(38.0, 35.0),(45.0, 28.0),(44.0, 36.0),

(50.0, 28.0),(25.0, 33.0),(30.0, 30.0),(27.0, 34.0),(51.0, 33.0),

(22.0, 32.0),(31.0, 31.0),(46.0, 29.0),(36.0, 29.0),(30.0, 32.0),

(40.0, 32.0),(38.0, 31.0),(44.0, 30.0),(24.0, 33.0),(49.0, 36.0),

(24.0, 31.0),(50.0, 35.0),(47.0, 34.0),(46.0, 30.0),(53.0, 33.0),

(26.0, 29.0),(52.0, 29.0),(34.0, 32.0),(36.0, 35.0),(33.0, 29.0),

(39.0, 29.0),(54.0, 31.0),(37.0, 34.0),(41.0, 31.0),(44.0, 35.0),

(45.0, 34.0),(26.0, 33.0),(24.0, 28.0),(46.0, 36.0),(52.0, 33.0),

(50.0, 36.0),(41.0, 28.0),(47.0, 33.0),(54.0, 36.0),(53.0, 36.0),

(26.0, 30.0),(29.0, 33.0),(22.0, 29.0),(31.0, 34.0),(27.0, 31.0),

(32.0, 29.0),(29.0, 29.0),(48.0, 35.0),(35.0, 30.0),(26.0, 34.0),

(49.0, 34.0),(22.0, 36.0),(40.0, 30.0),(46.0, 33.0),(28.0, 33.0),

(32.0, 36.0),(47.0, 36.0),(30.0, 36.0),(37.0, 28.0),(54.0, 33.0),

(29.0, 36.0),(42.0, 28.0),(23.0, 33.0),(40.0, 36.0),(33.0, 33.0),

(35.0, 34.0),(23.0, 31.0),(41.0, 33.0),(48.0, 31.0),(28.0, 29.0),

(43.0, 34.0),(49.0, 30.0),(50.0, 29.0),(51.0, 32.0),(22.0, 33.0),

(31.0, 30.0),(36.0, 30.0),(51.0, 30.0),(23.0, 36.0),(32.0, 33.0),

(30.0, 33.0),(37.0, 31.0),(31.0, 36.0),(38.0, 28.0),(53.0, 28.0),

(43.0, 28.0),(48.0, 28.0),(44.0, 31.0),(43.0, 33.0),(24.0, 34.0),

(45.0, 30.0),(25.0, 35.0),(50.0, 30.0),(27.0, 32.0),(25.0, 29.0),

(22.0, 34.0),(46.0, 31.0),(53.0, 32.0),(47.0, 30.0),(30.0, 34.0),

(52.0, 30.0),(34.0, 33.0),(33.0, 28.0),(42.0, 33.0),(39.0, 28.0),

(54.0, 28.0),(37.0, 33.0),(44.0, 28.0),(39.0, 34.0),(45.0, 33.0),

(47.0, 32.0),(29.0, 32.0),(27.0, 30.0),(34.0, 34.0),(32.0, 30.0),

(36.0, 33.0),(33.0, 31.0),(38.0, 36.0),(37.0, 36.0),(29.0, 28.0),

(44.0, 33.0),(34.0, 28.0),(25.0, 36.0),(48.0, 36.0),(39.0, 33.0),

(45.0, 36.0),(51.0, 36.0),(49.0, 33.0),(28.0, 34.0),(29.0, 35.0),

(33.0, 32.0),(42.0, 29.0),(22.0, 31.0),(31.0, 32.0),(23.0, 30.0),

(41.0, 32.0),(28.0, 30.0),(38.0, 33.0),(29.0, 31.0),(39.0, 36.0),

(30.0, 28.0),(48.0, 33.0),(27.0, 36.0),(26.0, 36.0),(35.0, 28.0),

(40.0, 28.0),(46.0, 35.0),(36.0, 31.0),(52.0, 36.0),(32.0, 34.0),

(54.0, 35.0),(33.0, 35.0),(42.0, 30.0),(40.0, 34.0),(35.0, 32.0),

(23.0, 29.0),(48.0, 29.0),(43.0, 32.0),(50.0, 31.0),(27.0, 35.0),

(25.0, 28.0),(50.0, 33.0),(22.0, 35.0),(31.0, 28.0),(46.0, 28.0),

(28.0, 36.0),(36.0, 28.0),(51.0, 28.0),(52.0, 31.0),(38.0, 30.0),

(53.0, 30.0),(39.0, 31.0),(54.0, 29.0),(37.0, 32.0),(44.0, 29.0),

(24.0, 32.0),(45.0, 32.0)]

for key in points:

self.state.add(key)

# inputs the coordinates for a Gosper Glider Gun on the grid

def glider_gun(self):

points = [(23.0, 51.0),(25.0, 51.0),(17.0, 51.0),(21.0, 53.0),(1.0, 51.0),

(36.0, 53.0),(13.0, 48.0),(11.0, 50.0),(22.0, 53.0),(12.0, 53.0),

(17.0, 52.0),(18.0, 51.0),(15.0, 51.0),(1.0, 52.0),(25.0, 55.0),

(16.0, 49.0),(2.0, 51.0),(22.0, 54.0),(21.0, 54.0),(23.0, 55.0),

(11.0, 52.0),(13.0, 54.0),(35.0, 54.0),(25.0, 50.0),(2.0, 52.0),

(11.0, 51.0),(17.0, 50.0),(22.0, 52.0),(21.0, 52.0),(14.0, 48.0),

(25.0, 56.0),(35.0, 53.0),(12.0, 49.0),(36.0, 54.0),(16.0, 53.0),

(14.0, 54.0)]

for key in points:

self.state.add(key)

# inputs the coordinates for a Sparky

def sparky(self):

points = [(63.0, 28.0),(78.0, 28.0),(73.0, 32.0),(48.0, 31.0),(67.0, 33.0),

(51.0, 27.0),(50.0, 29.0),(48.0, 32.0),(52.0, 28.0),(71.0, 31.0),

(58.0, 36.0),(74.0, 32.0),(69.0, 28.0),(74.0, 28.0),(56.0, 30.0),

(59.0, 26.0),(54.0, 34.0),(77.0, 34.0),(72.0, 34.0),(57.0, 31.0),

(60.0, 29.0),(53.0, 28.0),(58.0, 28.0),(74.0, 25.0),(66.0, 33.0),

(52.0, 32.0),(48.0, 28.0),(62.0, 31.0),(78.0, 32.0),(64.0, 31.0),

(55.0, 26.0),(70.0, 27.0),(69.0, 33.0),(72.0, 27.0),(75.0, 25.0),

(60.0, 26.0),(57.0, 34.0),(58.0, 25.0),(73.0, 26.0),(53.0, 32.0),

(51.0, 29.0),(54.0, 27.0),(70.0, 28.0),(56.0, 27.0),(50.0, 27.0),

(57.0, 26.0),(60.0, 33.0),(56.0, 32.0),(59.0, 28.0),(64.0, 28.0),

(57.0, 29.0),(60.0, 31.0),(64.0, 32.0),(63.0, 29.0),(71.0, 33.0),

(62.0, 29.0),(72.0, 29.0),(51.0, 33.0),(66.0, 27.0),(74.0, 35.0),

(51.0, 31.0),(62.0, 33.0),(56.0, 29.0),(75.0, 30.0),(72.0, 33.0),

(71.0, 27.0),(70.0, 33.0),(58.0, 32.0),(58.0, 31.0),(48.0, 27.0),

(61.0, 34.0),(59.0, 30.0),(72.0, 26.0),(63.0, 31.0),(59.0, 32.0),

(58.0, 24.0),(67.0, 32.0),(53.0, 33.0),(54.0, 26.0),(72.0, 31.0),

(75.0, 29.0),(55.0, 34.0),(48.0, 33.0),(57.0, 27.0),(69.0, 27.0),

(56.0, 31.0),(62.0, 27.0),(57.0, 30.0),(78.0, 30.0),(73.0, 34.0),

(53.0, 27.0),(58.0, 29.0),(77.0, 26.0),(75.0, 35.0),(48.0, 29.0),

(62.0, 28.0),(67.0, 28.0),(57.0, 33.0),(69.0, 32.0),(60.0, 27.0),

(50.0, 31.0),(59.0, 34.0),(71.0, 29.0),(61.0, 26.0),(50.0, 33.0),

(62.0, 32.0),(56.0, 28.0),(75.0, 31.0),(64.0, 29.0),(70.0, 32.0),

(73.0, 28.0),(58.0, 35.0),(60.0, 34.0),(56.0, 33.0),(54.0, 33.0),

(63.0, 32.0),(67.0, 27.0)]

for key in points:

screen = turtle.Screen()

turtle.mode('standard')

xspan, yspan = screen.screensize()

turtle.setworldcoordinates(0, 0, xspan, yspan)

# makes the turtle invisible, improves drawing speed

turtle.hideturtle()

# fastest speed for the drawing

turtle.speed('fastest')

# no tracing within turtle, improves drawing speed

turtle.tracer(0, 0)

# turtle pen is off the canvas to start

turtle.penup()

board = Grid(xspan // SIZE, yspan // SIZE)

def flip_state(x, y):

x_cell = x // SIZE

y_cell = y // SIZE

board.flip_state(x_cell,y_cell)

board.display()

turtle.onscreenclick(turtle.listen)

turtle.onscreenclick(flip_state)

def clear_board():

board.clear_board()

board.display()

# binds function to the 'e' key

turtle.onkey(clear_board, 'e')

# binds function to the 'q' key

turtle.onkey(sys.exit, 'q')

continuous = False

def step_once():

# allows for the rebinding of variables outside of the local scope

nonlocal continuous

continuous = False

perform_step()

def step_continuous():

nonlocal continuous

continuous = True

perform_step()

def perform_step():

board.step()

board.display()

if continuous:

# calls function in question after t milliseconds

turtle.ontimer(perform_step, 25)

# binds functions to the 's' and 'c' keys respectively

turtle.onkey(step_once, 's')

turtle.onkey(step_continuous, 'c')

# prints out the coordinates (keys) of the current live cells

def print_live():

board.print_keys()

turtle.onkey(print_live, 'p')

# draws a Glider in the upper left of the display

def draw_glider():

board.glider()

board.display()

turtle.onkey(draw_glider, '1')

# draws a Garden of Eden in the display

def draw_garden():

board.garden()

board.display()

turtle.onkey(draw_garden, '2')

# draws a Gosper Glider Gun in the display

def draw_glider_gun():

board.glider_gun()

board.display()

turtle.onkey(draw_glider_gun, '3')

# draws a Sparky in the display

def draw_sparky():

board.sparky()

board.display()

turtle.onkey(draw_sparky, '4')

# turtle listens for key events

turtle.listen()

# required last statement in a program using turtle graphics