Python Maze Game Treasure

import turtle
wn = turtle.Screen()
wn.setup(700,700)
wn.bgcolor("black")

#create pen
class Pen(turtle.Turtle):
  def __init__(self):
    turtle.Turtle.__init__(self)
    self.shape("square")
    self.color("blue")
    self.penup()
    self.speed(0)

class Player(turtle.Turtle):
  def __init__(self):
    turtle.Turtle.__init__(self)
    self.shape("square")
    self.color("Green")
    self.penup()
    self.speed(0)
    self.gold= 0

  def go_up(self):
    move_to_x=player.xcor()
    move_to_y=player.ycor() + 24

    if (move_to_x,move_to_y) not in walls:
      self.goto(move_to_x, move_to_y)

  def go_down(self):
    move_to_x=player.xcor()
    move_to_y=player.ycor() - 24

    if (move_to_x,move_to_y) not in walls:
      self.goto(move_to_x, move_to_y)

  def go_right(self):
    move_to_x=player.xcor() + 24
    move_to_y=player.ycor()

    if (move_to_x,move_to_y) not in walls:
      self.goto(move_to_x, move_to_y)

  def go_left(self):
    move_to_x=player.xcor() - 24
    move_to_y=player.ycor()

    if (move_to_x,move_to_y) not in walls:
      self.goto(move_to_x, move_to_y)

  def is_collision(self, other):
    a = self.xcor()-other.xcor()
    b = self.ycor()-other.ycor()
    distance = math.sqrt((a ** 2) + (b ** 2))

    if distance < 5:
      return True
    else:
      return False

class Treasure(turtle.Turtle):
  def _init_(self, x, y):
    turtle.Turtle._init_(self)
    self.shape("circle")
    self.color("gold")
    self.penup()
    self.speed(0)
    self.gold = 100
    self.goto(x, y)

def destroy(self):
  self.goto(2000, 2000)
#create Levels list
levels = [""]

#define first level
level_1 = [
"XXXXXXXXXXXXXXXXXXXXXXXXX",
"XP  XXXXXXX           TXX",
"X  XXXXXXX  XXXXXX     XX",
"X       XX  XXXXXX    XXX",
"X       XX  XXX        XX",
"X  XXX  XX  XXX        XX",
"X    X  XX  XXXXXX  XXXXX",
"XXXX X  XX    XXXX  XXXXX",
"X  X X          T       X",
"X       XX  XXXX      X X",
"X XXXXXXXX  XXXXXXXXXXX X",
"X                XX     X",
"XXXXXXXXXXXX     XXXTXXXX",
"X  TXXXXXXXXXXX  XXXXX  X",
"X XXXXXXXXXXXXX         X",
"X X                     X",
"X           XXXX  XXXXXXX",
"X XXXX  XXXXXXXX   XXXXXX",
"X XXXX  XX              X",
"X  T XXXXX              X",
"XX          XXXXXX  XX  X",
"XXXXXXXXXXXXXXXXXX  XX  X",
"XX   X       XXXXX      X",
"XXXX                    X",
"XXXXXXXXXXXXXXXXXXXXXXXXX"
]
#Add treasure list
treasures = []
#Add maze to mazes list
levels.append(level_1)

#Create Level Setup Function

def setup_maze(level):
  turtle.speed(0)
  for y in range(len(level)):
    for x in range(len(level[y])):
      #Get the Character at each x,y coordinate
      character = level[y][x]
      #Calculate the screen x, y coordinates
      screen_x = -288 + (x * 24)
      screen_y = 288 - (y * 24)

      #To check if it is an X (rep a wall)
      if character == "X":
        pen.goto(screen_x, screen_y)
        pen.stamp()
        walls.append((screen_x,screen_y))
       #To check if P (reps the player
      if character == "P":
        player.goto(screen_x, screen_y)
        #To check if T (reps the treasures)
      if character == "T":
        treasures.append(Treasure(screen_x, screen_y))

#Create class instances
pen = Pen()
player = Player()
# Walls
walls=[]
print(walls)

#Set up the level
setup_maze(levels[1])
print(walls)


#Keyboard Binding
wn.listen()
wn.onkey(player.go_left,"Left")
wn.onkey(player.go_right,"Right")
wn.onkey(player.go_up,"Up")
wn.onkey(player.go_down,"Down")


#Turn off screen upates
wn.tracer(0)


#Main Game Loop
while True:
    #Check collision with treasure
    #Iterate through treasure list
    for treasure in treasures:
      if player.is_collision(treasure):
           #Add treasure gold to plsyer gold
           player.gold += treasure.gold
           print ("Player GOld: {}".format(player.gold))
           #Destroys the treasure
           treasure.destroy()
           #Removes the treasure from the treasures list
           treasure.remove(treasure)
# Update Screen
    wn.update()