python从入门到精通中外星人入侵的小问题（为什么会出现“File Not Found Error"?)

我已经把图片放进alien_invasion 的images 的 ship.bmp了，但是就是出现不了小飞船图片。
球球大神帮助我这个萌新。

下边是报错的代码
```python
Traceback (most recent call last):
  File "C:\Users\bighead\PycharmProjects\pythonProject\alien_invasion\alien_invasion.py", line 22, in <module>
    run_game()

  File "C:\Users\bighead\PycharmProjects\pythonProject\alien_invasion\alien_invasion.py", line 15, in run_game
    ship = Ship(screen)

  File "C:\Users\bighead\PycharmProjects\pythonProject\alien_invasion\ship.py", line 9, in __init__
    self.image = pygame.image.load('images/ship.bmp')

FileNotFoundError: No such file or directory.

下边是ship.py的代码

```python
import pygame


class Ship:

    def __init__(self, screen):
        self.screen = screen

        self.image = pygame.image.load('images/ship.bmp')
        self.rect = self.image.get_rect()
        self.screen_rect = screen.get_rect()

        self.rect.centerx = self.screen_rect.centerx
        self.rect.bottom = self.screen_rect.bottom

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

运行路径不等于文件路径
需要使用

import os,sys
os.chdir(sys.path[0])

将路径同步到文件路径，之后可以正常使用相对位置