待办清单应用

开发实用的命令行任务管理工具

项目概述

功能需求

• 添加任务
• 查看任务列表
• 标记任务完成
• 删除任务
• 数据持久化保存

技能点

• CRUD操作
• 文件读写
• JSON数据处理
• 面向对象设计

---

版本1：基础版

# todo_v1.py
"""待办清单 - 基础版"""

todos = []

def add_task():
    task = input("请输入任务：").strip()
    if task:
        todos.append({"task": task, "done": False})
        print(f"✓ 任务已添加")
    else:
        print("任务不能为空")

def show_tasks():
    if not todos:
        print("暂无任务")
        return

    print("\n===== 待办清单 =====")
    for i, todo in enumerate(todos, 1):
        status = "✓" if todo["done"] else "○"
        print(f"{i}. [{status}] {todo['task']}")

def complete_task():
    show_tasks()
    if not todos:
        return

    try:
        index = int(input("完成第几个任务：")) - 1
        if 0 <= index < len(todos):
            todos[index]["done"] = True
            print("✓ 任务已完成")
        else:
            print("无效编号")
    except ValueError:
        print("请输入数字")

def delete_task():
    show_tasks()
    if not todos:
        return

    try:
        index = int(input("删除第几个任务：")) - 1
        if 0 <= index < len(todos):
            removed = todos.pop(index)
            print(f"✓ 已删除：{removed['task']}")
        else:
            print("无效编号")
    except ValueError:
        print("请输入数字")

def main():
    print("===== 待办清单 v1.0 =====")

    while True:
        print("\n1.添加 2.查看 3.完成 4.删除 5.退出")
        choice = input("请选择：")

        if choice == "1":
            add_task()
        elif choice == "2":
            show_tasks()
        elif choice == "3":
            complete_task()
        elif choice == "4":
            delete_task()
        elif choice == "5":
            print("再见！")
            break
        else:
            print("无效选择")

if __name__ == "__main__":
    main()

---

版本2：增加数据持久化

# todo_v2.py
"""待办清单 - 数据持久化版"""

import json
from datetime import datetime

class TodoList:
    def __init__(self, filename="todos.json"):
        self.filename = filename
        self.todos = []
        self.load()

    def load(self):
        """从文件加载数据"""
        try:
            with open(self.filename, "r", encoding="utf-8") as f:
                self.todos = json.load(f)
        except FileNotFoundError:
            self.todos = []

    def save(self):
        """保存数据到文件"""
        with open(self.filename, "w", encoding="utf-8") as f:
            json.dump(self.todos, f, ensure_ascii=False, indent=2)

    def add(self, task):
        """添加任务"""
        todo = {
            "id": len(self.todos) + 1,
            "task": task,
            "done": False,
            "created_at": datetime.now().strftime("%Y-%m-%d %H:%M")
        }
        self.todos.append(todo)
        self.save()
        print(f"✓ 已添加：{task}")

    def show(self, show_all=True):
        """显示任务列表"""
        if not self.todos:
            print("暂无任务")
            return

        print("\n" + "=" * 40)
        print("  待办清单")
        print("=" * 40)

        for i, todo in enumerate(self.todos, 1):
            if not show_all and todo["done"]:
                continue
            status = "✓" if todo["done"] else "○"
            print(f"{i}. [{status}] {todo['task']}")
            print(f"   创建于：{todo['created_at']}")

        # 统计
        total = len(self.todos)
        done = sum(1 for t in self.todos if t["done"])
        print(f"\n共 {total} 个任务，完成 {done} 个")

    def complete(self, index):
        """标记任务完成"""
        if 0 <= index < len(self.todos):
            self.todos[index]["done"] = True
            self.todos[index]["completed_at"] = datetime.now().strftime("%Y-%m-%d %H:%M")
            self.save()
            print(f"✓ 完成：{self.todos[index]['task']}")
        else:
            print("无效编号")

    def delete(self, index):
        """删除任务"""
        if 0 <= index < len(self.todos):
            removed = self.todos.pop(index)
            self.save()
            print(f"✓ 删除：{removed['task']}")
        else:
            print("无效编号")

    def clear_done(self):
        """清除已完成任务"""
        count = len([t for t in self.todos if t["done"]])
        self.todos = [t for t in self.todos if not t["done"]]
        self.save()
        print(f"✓ 已清除 {count} 个完成的任务")

def main():
    todo_list = TodoList()

    print("=" * 40)
    print("       待办清单 v2.0")
    print("=" * 40)

    while True:
        print("\n命令：add/list/done/del/clear/quit")
        cmd = input("> ").strip().lower()

        if cmd == "add":
            task = input("任务内容：").strip()
            if task:
                todo_list.add(task)
        elif cmd == "list":
            todo_list.show()
        elif cmd == "done":
            todo_list.show()
            try:
                index = int(input("完成第几个：")) - 1
                todo_list.complete(index)
            except ValueError:
                print("请输入数字")
        elif cmd == "del":
            todo_list.show()
            try:
                index = int(input("删除第几个：")) - 1
                todo_list.delete(index)
            except ValueError:
                print("请输入数字")
        elif cmd == "clear":
            todo_list.clear_done()
        elif cmd == "quit":
            print("再见！")
            break
        else:
            print("未知命令")

if __name__ == "__main__":
    main()

---

版本3：增加优先级和分类

# todo_v3.py
"""待办清单 - 完整版"""

import json
from datetime import datetime

class Task:
    def __init__(self, content, priority="中", category="默认"):
        self.id = None
        self.content = content
        self.priority = priority  # 高/中/低
        self.category = category
        self.done = False
        self.created_at = datetime.now().strftime("%Y-%m-%d %H:%M")
        self.completed_at = None

    def to_dict(self):
        return {
            "id": self.id,
            "content": self.content,
            "priority": self.priority,
            "category": self.category,
            "done": self.done,
            "created_at": self.created_at,
            "completed_at": self.completed_at
        }

    @classmethod
    def from_dict(cls, data):
        task = cls(data["content"], data["priority"], data["category"])
        task.id = data["id"]
        task.done = data["done"]
        task.created_at = data["created_at"]
        task.completed_at = data.get("completed_at")
        return task

class TodoApp:
    PRIORITY_ORDER = {"高": 0, "中": 1, "低": 2}

    def __init__(self, filename="todos_v3.json"):
        self.filename = filename
        self.tasks = []
        self.next_id = 1
        self.load()

    def load(self):
        try:
            with open(self.filename, "r", encoding="utf-8") as f:
                data = json.load(f)
                self.tasks = [Task.from_dict(t) for t in data["tasks"]]
                self.next_id = data.get("next_id", len(self.tasks) + 1)
        except FileNotFoundError:
            self.tasks = []

    def save(self):
        data = {
            "tasks": [t.to_dict() for t in self.tasks],
            "next_id": self.next_id
        }
        with open(self.filename, "w", encoding="utf-8") as f:
            json.dump(data, f, ensure_ascii=False, indent=2)

    def add_task(self, content, priority="中", category="默认"):
        task = Task(content, priority, category)
        task.id = self.next_id
        self.next_id += 1
        self.tasks.append(task)
        self.save()
        print(f"✓ 已添加任务 #{task.id}")

    def list_tasks(self, filter_category=None, show_done=True):
        tasks = self.tasks
        if filter_category:
            tasks = [t for t in tasks if t.category == filter_category]
        if not show_done:
            tasks = [t for t in tasks if not t.done]

        # 按优先级排序
        tasks = sorted(tasks, key=lambda t: self.PRIORITY_ORDER.get(t.priority, 1))

        if not tasks:
            print("暂无任务")
            return

        print("\n" + "=" * 50)
        for task in tasks:
            status = "✓" if task.done else "○"
            priority_mark = {"高": "🔴", "中": "🟡", "低": "🟢"}.get(task.priority, "")
            print(f"#{task.id} [{status}] {priority_mark} {task.content}")
            print(f"     分类：{task.category} | 创建：{task.created_at}")
        print("=" * 50)

    def complete_task(self, task_id):
        for task in self.tasks:
            if task.id == task_id:
                task.done = True
                task.completed_at = datetime.now().strftime("%Y-%m-%d %H:%M")
                self.save()
                print(f"✓ 任务 #{task_id} 已完成")
                return
        print("未找到任务")

    def delete_task(self, task_id):
        for i, task in enumerate(self.tasks):
            if task.id == task_id:
                self.tasks.pop(i)
                self.save()
                print(f"✓ 任务 #{task_id} 已删除")
                return
        print("未找到任务")

    def get_categories(self):
        return list(set(t.category for t in self.tasks))

    def stats(self):
        total = len(self.tasks)
        done = sum(1 for t in self.tasks if t.done)
        print(f"\n📊 统计：共{total}个任务，完成{done}个，剩余{total-done}个")

def main():
    app = TodoApp()

    print("=" * 50)
    print("         待办清单 v3.0")
    print("=" * 50)

    while True:
        print("\n命令: add | list | done | del | stats | quit")
        cmd = input("> ").strip().lower()

        if cmd == "add":
            content = input("任务内容：").strip()
            if not content:
                continue
            print("优先级 (高/中/低，默认中)：", end="")
            priority = input().strip() or "中"
            print("分类（默认：默认）：", end="")
            category = input().strip() or "默认"
            app.add_task(content, priority, category)

        elif cmd == "list":
            app.list_tasks()

        elif cmd == "done":
            app.list_tasks(show_done=False)
            try:
                task_id = int(input("完成任务ID："))
                app.complete_task(task_id)
            except ValueError:
                print("请输入数字")

        elif cmd == "del":
            app.list_tasks()
            try:
                task_id = int(input("删除任务ID："))
                app.delete_task(task_id)
            except ValueError:
                print("请输入数字")

        elif cmd == "stats":
            app.stats()

        elif cmd == "quit":
            print("再见！")
            break

if __name__ == "__main__":
    main()

---

本章小结

通过这个项目，你学会了：

1. CRUD操作：增删改查
2. JSON存储：数据持久化
3. 类的设计：面向对象封装
4. 数据结构：列表和字典的使用
5. 用户交互：命令行界面设计

---

下一步

完成待办清单，下一章学习数据分析入门。

→ 继续阅读：29-数据分析入门项目