title: Pygame Rect Collision
body: <p>I am creating a game of Pong in Pygame with Python (obviously) and am new to Pygame so would like some help working the physics of when the ball touches the paddle, it will reverse speeds and go the opposite direction. Everything works so far, but when the ball goes to the paddle, it goes right through it and does not change direction. I have it worked out so the paddles do not leave the screen and the ball changes direction when it meets a wall, but not when the ball meets a paddle. Any help or tips would be appreciated.</p>
  
  <p>My paddle class:</p>
  
  <pre><code>class Paddle:    
      def __init__(self, x, y):    
          self.x = x
          self.y = y
          self.height = 40
          self.width = 10
  
      def draw(self, canvas):
           pygame.draw.rect(canvas, pygame.Color(0,0,255),(self.x,self.y,self.width,self.height))
      def contains(self, ptX, ptY):
          return self.x &lt; ptX &lt; self.x + self.width &amp; self.y &lt; ptY &lt; self.y + self.height
      def overlaps(self, otherRectangle):
          return otherRectangle.colliderect(Rect(self.x,self.y,self.height, self.width))
  </code></pre>
  
  <p>My ball class</p>
  
  <pre><code>class Ball:
      def __init__(self, x, y):    
          #position of ball
          self.x = x
          self.y = y
  
          #speed of ball
          self.dx = 5
          self.dy = 5
  
          self.height = 10
          self.width = 10
  
      def draw(self, canvas):
          pygame.draw.rect(canvas, pygame.Color(0,255,0), (self.x,self.y,self.width,self.height))
  
      def reset(self):
          self.x = 320
          self.y = 240
  
          self.dx = -self.dx
          self.dy = 5
  </code></pre>
  
  <p>My goal is to have the speed of the ball reverse (negative speed) when it touches the paddle or bounces off (overlapping points).</p>