diff --git a/alien_invasion.py b/alien_invasion.py
index 8ecb28b..64d3d92 100644
--- a/alien_invasion.py
+++ b/alien_invasion.py
@@ -34,18 +34,18 @@ def run_game():
 
     # 开始游戏主循环
     while True:
-        # 监视键盘和鼠标事件
-        gf.check_events(ai_settings, screen, stats, sb, play_button, ship, aliens, bullets)
+    # 监视键盘和鼠标事件
+    gf.check_events(ai_settings, screen, stats, sb, play_button, ship, aliens, bullets)
 
-        if stats.game_active:
-            # 移动飞船
-            gf.update_ship(ship)
-            # 更新子弹位置
-            gf.update_bullets(ai_settings, screen, stats, sb, ship, aliens, bullets)
-            # 更新外星人
-            gf.update_aliens(ai_settings, stats, screen, sb, ship, aliens, bullets)
-        # 更新屏幕
-        gf.update_screen(ai_settings, screen, stats, sb, ship, aliens, bullets, play_button)
+    if stats.game_active:
+        # 移动飞船
+        gf.update_ship(ship)
+        # 更新子弹位置
+        gf.update_bullets(ai_settings, screen, stats, sb, ship, aliens, bullets)
+        # 更新外星人
+        gf.update_aliens(ai_settings, stats, screen, sb, ship, aliens, bullets)
+    # 更新屏幕
+    gf.update_screen(ai_settings, screen, stats, sb, ship, aliens, bullets, play_button)
 
 
 run_game()
\ No newline at end of file
diff --git a/bullet.py b/bullet.py
index 3deba69..c3ac79b 100644
--- a/bullet.py
+++ b/bullet.py
@@ -2,30 +2,33 @@ import pygame
 from pygame.sprite import Sprite
 import time
 
+
 class Bullet(Sprite):
     '''飞船子弹进行管理'''
 
-    def __init__(self,ai_settings,screen,ship):
-        super(Bullet,self).__init__()
-        self.screen = screen
+    def __init__(self, ai_settings, screen, ship):
+        super(Bullet, self).__init__()
 
-        # 创建子弹矩形初始位置（0,0,3,15）分别对应lef，top，宽，高
-        self.rect = pygame.Rect(0,0,
-        ai_settings.bullet_width, ai_settings.bullet_height)
+    self.screen = screen
 
-        self.rect.centerx = ship.rect.centerx  # 设置中心点x轴坐标跟飞船一致
-        self.rect.top = ship.rect.top          # 设置y轴坐标顶部跟飞船一致
+    # 创建子弹矩形初始位置（0,0,3,15）分别对应lef，top，宽，高
+    self.rect = pygame.Rect(0, 0,
+                            ai_settings.bullet_width, ai_settings.bullet_height)
 
-        # 设置成小数进行计算
-        self.top = float(self.rect.top)
+    self.rect.centerx = ship.rect.centerx  # 设置中心点x轴坐标跟飞船一致
+    self.rect.top = ship.rect.top  # 设置y轴坐标顶部跟飞船一致
 
-        self.color = ai_settings.bullet_color
-        self.speed_factor = ai_settings.bullet_speed_factor
+    # 设置成小数进行计算
+    self.top = float(self.rect.top)
+
+    self.color = ai_settings.bullet_color
+    self.speed_factor = ai_settings.bullet_speed_factor
 
     def update(self):
-        self.top -=self.speed_factor
-        self.rect.top = self.top
-        print(self.rect.top)
+        self.top -= self.speed_factor
+
+    self.rect.top = self.top
+    print(self.rect.top)
 
     def draw_bullet(self):
-        pygame.draw.rect(self.screen,self.color,self.rect)
\ No newline at end of file
+        pygame.draw.rect(self.screen, self.color, self.rect)
\ No newline at end of file