title: Collision issue on Python snake game
body: <p>Have an issue with a game of snake in Python im making where my collision check isnt working. I have written a function to check a collision between the snake and the food itself. When it collides it doesnt do anything, i have written it to undraw if it collides using the function, i also put in a print function to see if the function was working if i was using it and saw no print.</p>
  
  <pre><code>def collide(block1,block2):
       if math.sqrt(((block2.getCenterX() - block1.getCenterX()) **2)+ ((block2.getCenterY() - block1.getCenterY())**2)) &lt; BLOCK_SIZE:
           print("true")
           return True
       else:
           return False
   ------------------------------------------------------- not part of functiom
      if collide(theSnake[0],food) == True:
      food.undraw()
      foodX = random.randint(BLOCK_SIZE, WIN_WIDTH-BLOCK_SIZE)
      foodY = random.randint(BLOCK_SIZE, WIN_HEIGHT-BLOCK_SIZE)
      food.draw()
      theSnake.append(block)
  
      else:
      foodX = foodX
      foodY = foodY
  </code></pre>