invader.py

import pygame
from shooter_bullet import Shooter_bullet
import random

class Invader(pygame.sprite.Sprite):

    def __init__(self, screen, number = 1, shooter_bullets = None):
        super(Invader, self).__init__()
        self.screen = screen
        self.shooter_bullets = shooter_bullets
        invader_path = f"icons/saucer{number}b.ico"
        self.image = pygame.image.load(invader_path)
        self.rect = self.image.get_rect()
        self.rect.x = self.rect.width
        self.rect.y = self.rect.height
        self.x = float(self.rect.x)
        self.y = float(self.rect.y)
        self.count_move = 150
        self.move_x = 0.4
        self.number = number
        self.is_shooter = (number == 3)

    def print(self):
        self.screen.blit(self.image, self.rect)

    def update(self, shift=50):
        rnd = random.randint

        if self.count_move < 400:
            self.count_move += 1
            self.x += self.move_x
        else:
            self.count_move = 0
            self.y += 4
            self.move_x = -self.move_x

        if self.is_shooter and rnd(0, 500) == 0:
            shooter_bullet = Shooter_bullet(self.screen, self)
            self.shooter_bullets.add(shooter_bullet)

        if self.is_shooter:
            shift.shift = self.y
        self.rect.x = self.x
        self.rect.y = self.y