refactor code structure

module/player.py

@@ -0,0 +1,23 @@
+# 玩家类
+from module import WIDTH, HEIGHT, JUMP_FORCE
+
+
+class Player:
+    def __init__(self):
+        self.x = WIDTH // 2
+        self.y = HEIGHT // 2
+        self.velocity = 0
+        self.on_ground = False
+        self.selected_block = "grass"
+
+    def move(self, dx, dy):
+        new_x = self.x + dx
+        new_y = self.y + dy
+        if 0 <= new_x < WIDTH and 0 <= new_y < HEIGHT:
+            self.x = new_x
+            self.y = new_y
+
+    def jump(self):
+        if self.on_ground:
+            self.velocity = JUMP_FORCE
+            self.on_ground = False