How to rotate image while moving in pygame

Question

I am new to pygame and trying to develop a game in which the player moves with arrow keys and rotates around with the position of mouse (like mini miltia). But I am able to rotate the player but not able to move it around. It is only showing the player with rotation but it is not moving.

def rot_center(image, rect, angle):

    rot_image = pygame.transform.rotate(image, angle)
    rot_rect = rot_image.get_rect(center=rect.center)
    return rot_image, rot_rect

class Player(pygame.sprite.Sprite):

    def __init__(self):
        pygame.sprite.Sprite.__init__(self)
        self.image_orig = load_image('player.png')
        self.image = self.image_orig
        self.rect = self.image.get_rect()
        self.rect_orig = self.rect
        self.mask = pygame.mask.from_surface(self.image)
        self.x, self.y = int(pygame.display.Info().current_w / 2), int(pygame.display.Info().current_h / 2)
        self.rect.topleft = self.x, self.y
        self.health = 100
        self.damage_done = 0
        self.chspeed_x = 10
        self.chspeed_y = 10
        self.dir = 0

    def rot_aim(self, tx, ty):
        self.dir = (math.atan2(self.y - ty, self.x - tx) * 180 / PI)
        self.image, self.rect = rot_center(self.image_orig, self.rect_orig, self.dir)

    def move(self, dx, dy):
        self.chspeed_x = dx
        self.chspeed_y = dy
        self.x = self.x + self.chspeed_x * math.cos(math.radians(270 - self.dir))
        self.y = self.y + self.chspeed_y * math.cos(math.radians(270 - self.dir))

def main():

    pygame.init()
    screen = pygame.display.set_mode((800, 600))
    clock = pygame.time.Clock()
    FPS = 30
    paused = False
    player = Player()

    player_s = pygame.sprite.Group()

    player_s.add(player)

    while not paused:

        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                pygame.quit()
                quit()
            if event.type == pygame.MOUSEMOTION:
                mousepos = pygame.mouse.get_pos()
                mouseX = mousepos[0]
                mouseY = mousepos[1]
                player.rot_aim(mousepos[1], mousepos[0])
            if event.type == pygame.KEYDOWN:
                if event.type == pygame.K_UP:
                    player.move(0, 10)
                if event.type == pygame.K_DOWN:
                    player.move(0, -10)
                if event.type == pygame.K_RIGHT:
                    player.move(10, 0)
                if event.type == pygame.K_LEFT:
                    player.move(-10, 0)

        player_s.draw(screen)
        clock.tick(FPS)
        pygame.display.flip()

Answer 1

You missed to update self.rect after rotating or moving the player. Actually the position of the player ( self.x , self.y ) is changed. But since self.rect is used to draw the player, this attribute has to be updated by the position. The position has to be round , because a pygame.Rect object stores integral values:

class Player(pygame.sprite.Sprite):
    # [...]

    def rot_aim(self, tx, ty):
        self.dir = (math.atan2(self.y - ty, self.x - tx) * 180 / PI)
        self.image, self.rect = rot_center(self.image_orig, self.rect_orig, self.dir)

        self.rect.center = round(self.x), round(self.y) # <--- this is missing

    def move(self, dx, dy):
        self.chspeed_x = dx
        self.chspeed_y = dy
        self.x = self.x + self.chspeed_x * math.cos(math.radians(270 - self.dir))
        self.y = self.y + self.chspeed_y * math.cos(math.radians(270 - self.dir))

        self.rect.center= round(self.x), round(self.y) # <--- this is missing

---

Further more there is a typo. You have to compare event.key to the button rather than event.type

For instance:

if event.type == pygame.K_UP:

if event.key == pygame.K_UP:
    # [...]

---

Anyway I recommend to use pygame.key.get_pressed() rather than the button events, to achieve a continuously and smooth movement.
Finally clear the background by screen.fill(0) before drawing the scene:

def main():

    # [...]

    while not paused:

        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                pygame.quit()
                quit()
            if event.type == pygame.MOUSEMOTION:
                mousepos = pygame.mouse.get_pos()
                mouseX = mousepos[0]
                mouseY = mousepos[1]
                player.rot_aim(mousepos[1], mousepos[0])

        keys = pygame.key.get_pressed()
        if keys[pygame.K_UP]:
            player.move(0, -10)
        if keys[pygame.K_DOWN]:
            player.move(0, 10)
        if keys[pygame.K_RIGHT]:
            player.move(10, 0)
        if keys[pygame.K_LEFT]:
            player.move(-10, 0)

        screen.fill(0)
        player_s.draw(screen)
        clock.tick(FPS)
        pygame.display.flip()