From fd719120ff73df0003ceab4b41ecb96861817e1c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E7=8E=8B=E5=A0=83=E8=90=A5?= <1572506709@qq.com>
Date: Wed, 7 Oct 2026 23:52:42 +0800
Subject: [PATCH] =?UTF-8?q?=E7=BC=96=E7=A8=8B=E9=A2=982=EF=BC=9A=E7=94=A8?=
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---
 q2/main.py | 58 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 58 insertions(+)
 create mode 100644 q2/main.py

diff --git a/q2/main.py b/q2/main.py
new file mode 100644
index 0000000..ceed9a4
--- /dev/null
+++ b/q2/main.py
@@ -0,0 +1,58 @@
+import json
+
+
+class UserManager:
+    """管理用户数据的增删查改，并支持 JSON 文件保存和加载。"""
+
+    def __init__(self):
+        self.users = []      # 存放所有用户字典
+        self.next_id = 1     # 下一个要分配的 id
+
+    def add_user(self, name, age):
+        """添加用户，自动分配 id，返回该用户字典。"""
+        user = {"id": self.next_id, "name": name, "age": age}
+        self.users.append(user)
+        self.next_id += 1
+        return user
+
+    def get_user(self, user_id):
+        """按 id 查询用户，不存在返回 None。"""
+        for user in self.users:
+            if user["id"] == user_id:
+                return user
+        return None
+
+    def update_age(self, user_id, age):
+        """修改用户年龄，成功返回 True，不存在返回 False。"""
+        for user in self.users:
+            if user["id"] == user_id:
+                user["age"] = age
+                return True
+        return False
+
+    def remove_user(self, user_id):
+        """删除用户，成功返回 True，不存在返回 False。"""
+        for user in self.users:
+            if user["id"] == user_id:
+                self.users.remove(user)
+                return True
+        return False
+
+    def list_users(self):
+        """列出所有用户（按添加顺序）。"""
+        return self.users
+
+    def save_to_json(self, filepath):
+        """把所有用户保存为 JSON 文件。"""
+        with open(filepath, "w", encoding="utf-8") as f:
+            json.dump(self.users, f, ensure_ascii=False, indent=2)
+
+    def load_from_json(self, filepath):
+        """从 JSON 文件加载用户，覆盖当前数据。"""
+        with open(filepath, "r", encoding="utf-8") as f:
+            self.users = json.load(f)
+        # 后续添加的 id 接续已加载的最大 id
+        if self.users:
+            self.next_id = max(user["id"] for user in self.users) + 1
+        else:
+            self.next_id = 1