ship.py

import pygame
from pygame.sprite import Sprite

class Ship(Sprite):
	
	def __init__(self, ai_settings, screen):
		"""Initialize the ship and set its starting position."""
		super().__init__()
		self.screen = screen
		self.ai_settings = ai_settings
		#Load the ship image and get its rect.
		self.image = pygame.image.load('images/ship.png')
		self.rect = self.image.get_rect()
		self.screen_rect = screen.get_rect()
		
		# Start new ship at the bottom center of the screen.
		self.rect.centerx = self.screen_rect.centerx
		self.rect.bottom = self.screen_rect.bottom
		
		# Store decimal value for the ship's center.
		self.center = float(self.rect.centerx)
		
		# Movement flag
		self.moving_right = False
		self.moving_left = False
		
				
	def update(self):
		"""Update the ship's position based on the movement flag."""
		# Update the ship's center value, not the rect.
		"""if self.moving_right:"""
		"""self.rect.centerx += 1"""
		if self.moving_right and self.rect.right < self.screen_rect.right:
			self.center += self.ai_settings.ship_speed_factor 
		"""if self.moving_left:"""
		"""self.rect.centerx -= 1"""
		if self.moving_left and self.rect.left > 0:
			self.center -= self.ai_settings.ship_speed_factor
			
		# Update rect object from self.center
		self.rect.centerx = self.center
		
	def blitme(self):
		"""Draw the  ship and its current location."""
		self.screen.blit(self.image, self.rect)
		
	def center_ship(self):
		"""Center the ship on the screen."""
		self.center = self.screen_rect.centerx