Add collision detection to sprite, pyGame

Question

bassically im trying to add collision detection to the sprite below, using the following:

self.rect = bounds_rect


                collide = pygame.sprite.spritecollide(self, wall_list, False)

                if collide:
            # yes

                     print("collide")

However it seems that when the collide is triggered it continuously prints 'collide' over and over when instead i want them to simply not be able to walk through the object, any help?

def update(self, time_passed):
        """ Update the creep.

            time_passed:
                The time passed (in ms) since the previous update.
        """
        if self.state == Creep.ALIVE:
            # Maybe it's time to change the direction ?
            #
            self._change_direction(time_passed)

            # Make the creep point in the correct direction.
            # Since our direction vector is in screen coordinates 
            # (i.e. right bottom is 1, 1), and rotate() rotates 
            # counter-clockwise, the angle must be inverted to 
            # work correctly.
            #
            self.image = pygame.transform.rotate(
                self.base_image, -self.direction.angle)

            # Compute and apply the displacement to the position 
            # vector. The displacement is a vector, having the angle
            # of self.direction (which is normalized to not affect
            # the magnitude of the displacement)
            #
            displacement = vec2d(    
                self.direction.x * self.speed * time_passed,
                self.direction.y * self.speed * time_passed)

            self.pos += displacement

            # When the image is rotated, its size is changed.
            # We must take the size into account for detecting 
            # collisions with the walls.
            #
            self.image_w, self.image_h = self.image.get_size()
            global bounds_rect
            bounds_rect = self.field.inflate(
                            -self.image_w, -self.image_h)

            if self.pos.x < bounds_rect.left:
                self.pos.x = bounds_rect.left
                self.direction.x *= -1
            elif self.pos.x > bounds_rect.right:
                self.pos.x = bounds_rect.right
                self.direction.x *= -1
            elif self.pos.y < bounds_rect.top:
                self.pos.y = bounds_rect.top
                self.direction.y *= -1
            elif self.pos.y > bounds_rect.bottom:
                self.pos.y = bounds_rect.bottom
                self.direction.y *= -1

            self.rect = bounds_rect


            collide = pygame.sprite.spritecollide(self, wall_list, False)

            if collide:
        # yes

                 print("collide")




        elif self.state == Creep.EXPLODING:
            if self.explode_animation.active:
                self.explode_animation.update(time_passed)
            else:
                self.state = Creep.DEAD
                self.kill()

        elif self.state == Creep.DEAD:
            pass

        #------------------ PRIVATE PARTS ------------------#

    # States the creep can be in.
    #
    # ALIVE: The creep is roaming around the screen
    # EXPLODING: 
    #   The creep is now exploding, just a moment before dying.
    # DEAD: The creep is dead and inactive
    #
    (ALIVE, EXPLODING, DEAD) = range(3)

    _counter = 0

    def _change_direction(self, time_passed):
        """ Turn by 45 degrees in a random direction once per
            0.4 to 0.5 seconds.
        """
        self._counter += time_passed
        if self._counter > randint(400, 500):
            self.direction.rotate(45 * randint(-1, 1))
            self._counter = 0

    def _point_is_inside(self, point):
        """ Is the point (given as a vec2d) inside our creep's
            body?
        """
        img_point = point - vec2d(  
            int(self.pos.x - self.image_w / 2),
            int(self.pos.y - self.image_h / 2))

        try:
            pix = self.image.get_at(img_point)
            return pix[3] > 0
        except IndexError:
            return False

    def _decrease_health(self, n):
        """ Decrease my health by n (or to 0, if it's currently
            less than n)
        """
        self.health = max(0, self.health - n)
        if self.health == 0:
            self._explode()

    def _explode(self):
        """ Starts the explosion animation that ends the Creep's
            life.
        """
        self.state = Creep.EXPLODING
        pos = ( self.pos.x - self.explosion_images[0].get_width() / 2,
                self.pos.y - self.explosion_images[0].get_height() / 2)
        self.explode_animation = SimpleAnimation(
            self.screen, pos, self.explosion_images,
            100, 300)
        global remainingCreeps

        remainingCreeps-=1

        if remainingCreeps == 0:
                print("all dead")

Answer 1

A check for collision is only a check to see if two rectangular sprites have a common area. There isn't a built in collision that unables player input during collision. You have to write that yourself.

You should probably want to change the player coordinates when a collision takes place. An example:

Let's say we play mario. When the state of mario is JUMPING check for collision. Somewhere we will store the speed of mario in the y axis. When the collision returns True, with any of the blocks, we now set the speed to 0, and the y to the top/bottom of a block. If it will be the bottom, we still keep JUMPING, so it can fall back to the ground.

My tip for the creeper is to have some oldx and oldy value, to return to when the collision takes place. That way the creeper will never go into a wall. Another approach would be to simply change the direction when a collision takes place, but that may not always work.