bullet.py

import pygame
from pygame.sprite import Sprite

class Bullet(Sprite):
    """A class to manage bullets fired from the ship"""

    def __init__(self, ai_game):
        """Create  a bullet object at the ship's current position"""
        super().__init__()
        self.screen = ai_game.screen
        self.settings = ai_game.settings
        self.color = self.settings.bullet_color

        #create a bullet rect at (0,0) and then set correct position.

        self.rect = pygame.Rect(0,0,self.settings.bullet_width,self.settings.bullet_height)
        self.rect.midtop = ai_game.ship.rect.midtop

        #Store the bullet's position as a decimal value.
        self.y = float(self.rect.y)
    
    def update(self):
        """Move the bullet up the screen."""
        #update the decimal position of the bullet.
        self.y -= self.settings.bullet_speed
        #update the rect position.
        self.rect.y= self.y

    def draw_bullet(self):
        """Draw the bullet to screen."""
        pygame.draw.rect(self.screen, self.color, self.rect)