title: TypeError: __init__() missing 2 required positional arguments: 'x' and 'y' for bullet shooting system
body: <p>When I run this bit of code, it says that I have an error:</p>
  
  <pre><code>TypeError: __init__() missing 2 required positional arguments: 'x' and 'y'
  </code></pre>
  
  <p>I call the class and added them to a group:</p>
  
  <pre><code>kunai = Kunai()
  kunai_sprites = pg.sprite.Group() #puts all the kunai sprites into a group
  </code></pre>
  
  <p>Here is the class:</p>
  
  <pre><code>#throwing projectile (kunai)
  class Kunai(pg.sprite.Sprite): #creating the kunai class
      def __init__(self, x, y): #initialising the kunai
          pg.sprite.Sprite.__init__(self)
          self.image = pg.Surface((10,20))
          self.image.fill(RED)
          self.velocity = 35
          self.rect = self.image.get_rect()
          self.rect.bottom = y
          self.rect.centrex = x
  
  #drawing a circle which will determine the throwing range of the kunai
      def update(self):
          self.rect.y = self.rect.y + self.velocity #the kunai moves at set speed
          if self.rect.bottom &lt; 0: #if the sprite crosses 
              self.kill() #it removes the sprite
  </code></pre>