How do I move a laser bullet in a top down shooter in a certain direction?

Question

I am making a game in Pygame which requires the player to defend the Earth from aliens that are attacking it. The player is controlled with the arrow keys and the spacebar is used to shoot. So far everything is working fine except for the lasers. When I fire the laser, I wish for them to move in the direction the player is facing.

Here is my lazer class:

class lazer(pygame.sprite.Sprite):
    def __init__(self):
        super(lazer, self).__init__()
        self.image = pygame.image.load('lazer.png')
        self.rect = self.image.get_rect()
    def update1(self):
        keyy = pygame.key.get_pressed()
        speed = 30
        if keyy[pygame.K_UP]:
            self.rect.y -= speed 
        elif keyy[pygame.K_DOWN]:
            self.rect.y += speed
        if keyy[pygame.K_RIGHT]:
            self.rect.x += speed
        elif keyy[pygame.K_LEFT]:
            self.rect.x -= speed

So far the laser only moves when the player presses an arrow key. If the player stops pressing the arrow key, the laser will also stop moving and if the player moves in a different direction, the laser will also move in that direction.

Here is my full game code:

while GameOn == True:
    Player1.background(gameDisplay)
    if len(EnemyAliens) < 1:
        pygame.time.delay(3000)
        wave = wave + 1
        diff = diff + wave
        for i in range(diff):
            block = Aliens()
            block.rect.y = random.randrange(200, DisplayHeight-10)
            block.rect.x = random.randrange(110, DisplayWidth-10)
            EnemyAliens.add(block)
            all_sprites.add(block)
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            pygame.quit()
            quit
        if event.type == pygame.KEYDOWN:
            if event.key == pygame.K_SPACE:
                keyy = pygame.key.get_pressed()
                print(direction)
                lazer1 = lazer()
                lazer1.rect.y = Player1.rect.y
                lazer1.rect.x = Player1.rect.x
                all_sprites.add(lazer1)
                lazer_list.add(lazer1)
    for lazer1 in lazer_list:
        block_hit_list = pygame.sprite.spritecollide(lazer1, EnemyAliens, True)
        for block in block_hit_list:
            lazer_list.remove(lazer1)
            all_sprites.remove(lazer1)
            score += 1
            print(score)
        if lazer1.rect.y<-10 or lazer1.rect.y > DisplayHeight + 10 or lazer1.rect.x < -10 or lazer1.rect.x > DisplayWidth +10:
            lazer_list.remove(lazer1)
            all_sprites.remove(lazer1)
    for block in EnemyAliens:
        speed = 3
        if block.rect.x > 115:
            block.rect.x -= speed
        elif block.rect.x < 115:
            block.rect.x += speed
        if block.rect.y < 91:
            block.rect.y += speed
        elif block.rect.y > 91:
            block.rect.y -= speed
        col = pygame.sprite.collide_rect(Earth1,block)
        if col == True:
            all_sprites.remove(block)
            EnemyAliens.remove(block)
            earth_health -= 10
    for Pl in PlayerList:
        key = pygame.key.get_pressed()
        speed = 6
        direction = "w"          
        if key[pygame.K_UP]:
            Pl.rect.y -= speed
            direction = "U"
        elif key[pygame.K_DOWN]:
            Pl.rect.y += speed
            direction = "D"
        if key[pygame.K_RIGHT]:
            Pl.rect.x += speed
            direction = "R"
        elif key[pygame.K_LEFT]:
            Pl.rect.x -= speed
            direction = "L"
    if earth_health == 0 or earth_health < 0:
        if score > Highscore:
            saveHs(score)
        GameOn = False  
    HealthBars(earth_health)
    all_sprites.update()
    all_sprites.draw(gameDisplay)
    PlayerList.draw(gameDisplay)
    pygame.display.update()

How can I get the laser to move in the direction the player was moving, and not move along with the player?