目录

Python实例题

题目

要求：

解题思路：

代码实现：

Python实例题

题目

基于 Flask 的任务管理系统

要求：

• 使用 Flask 框架构建一个任务管理系统，支持以下功能：
  • 用户认证（注册、登录、注销）
  • 任务的创建、编辑、删除和标记完成
  • 任务分类和优先级管理
  • 任务截止日期和提醒功能
  • 任务统计和可视化分析
• 使用 SQLite 数据库存储用户、任务等信息。
• 添加美观的前端界面，支持响应式设计。

解题思路：

• 使用 Flask 蓝图组织代码结构。
• 通过 Flask-Login 处理用户认证。
• 使用 Flask-SQLAlchemy 管理数据库操作。
• 结合 Bootstrap 和 Chart.js 实现数据可视化。

代码实现：

from flask import Flask, render_template, request, redirect, url_for, flash, Blueprint
from flask_sqlalchemy import SQLAlchemy
from flask_login import LoginManager, UserMixin, login_user, logout_user, login_required, current_user
from werkzeug.security import generate_password_hash, check_password_hash
from datetime import datetime, timedelta
import os# 初始化 Flask 应用
app = Flask(__name__)
app.config['SECRET_KEY'] = 'your-secret-key-here'
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///' + os.path.join(app.root_path, 'task_manager.db')
app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = False# 初始化数据库
db = SQLAlchemy(app)# 初始化 Flask-Login
login_manager = LoginManager()
login_manager.init_app(app)
login_manager.login_view = 'auth.login'# 数据模型
class User(UserMixin, db.Model):id = db.Column(db.Integer, primary_key=True)username = db.Column(db.String(80), unique=True, nullable=False)password_hash = db.Column(db.String(120), nullable=False)tasks = db.relationship('Task', backref='user', lazy=True)def set_password(self, password):self.password_hash = generate_password_hash(password)def check_password(self, password):return check_password_hash(self.password_hash, password)class Category(db.Model):id = db.Column(db.Integer, primary_key=True)name = db.Column(db.String(50), nullable=False)user_id = db.Column(db.Integer, db.ForeignKey('user.id'), nullable=False)tasks = db.relationship('Task', backref='category', lazy=True)def __repr__(self):return self.nameclass Task(db.Model):id = db.Column(db.Integer, primary_key=True)title = db.Column(db.String(100), nullable=False)description = db.Column(db.Text)created_at = db.Column(db.DateTime, nullable=False, default=datetime.utcnow)due_date = db.Column(db.DateTime)completed = db.Column(db.Boolean, default=False)priority = db.Column(db.Integer, default=1)  # 1: 低, 2: 中, 3: 高user_id = db.Column(db.Integer, db.ForeignKey('user.id'), nullable=False)category_id = db.Column(db.Integer, db.ForeignKey('category.id'))def is_overdue(self):return self.due_date and not self.completed and datetime.now() > self.due_datedef is_due_soon(self):return self.due_date and not self.completed and datetime.now() < self.due_date and \self.due_date - datetime.now() <= timedelta(days=1)# 用户加载回调
@login_manager.user_loader
def load_user(user_id):return User.query.get(int(user_id))# 认证蓝图
auth = Blueprint('auth', __name__)@auth.route('/register', methods=['GET', 'POST'])
def register():if request.method == 'POST':username = request.form['username']password = request.form['password']if User.query.filter_by(username=username).first():flash('用户名已存在', 'error')return redirect(url_for('auth.register'))user = User(username=username)user.set_password(password)db.session.add(user)db.session.commit()# 为新用户创建默认分类default_category = Category(name='默认', user_id=user.id)db.session.add(default_category)db.session.commit()flash('注册成功，请登录', 'success')return redirect(url_for('auth.login'))return render_template('register.html')@auth.route('/login', methods=['GET', 'POST'])
def login():if request.method == 'POST':username = request.form['username']password = request.form['password']user = User.query.filter_by(username=username).first()if user and user.check_password(password):login_user(user)flash('登录成功', 'success')return redirect(url_for('main.dashboard'))else:flash('用户名或密码错误', 'error')return render_template('login.html')@auth.route('/logout')
@login_required
def logout():logout_user()flash('已注销', 'success')return redirect(url_for('auth.login'))# 主蓝图
main = Blueprint('main', __name__)@main.route('/')
@login_required
def dashboard():# 获取用户的任务统计数据total_tasks = Task.query.filter_by(user_id=current_user.id).count()completed_tasks = Task.query.filter_by(user_id=current_user.id, completed=True).count()pending_tasks = total_tasks - completed_tasks# 获取即将到期的任务due_soon_tasks = Task.query.filter_by(user_id=current_user.id, completed=False) \.filter(Task.due_date <= datetime.now() + timedelta(days=1)) \.order_by(Task.due_date).all()# 获取逾期任务overdue_tasks = Task.query.filter_by(user_id=current_user.id, completed=False) \.filter(Task.due_date < datetime.now()) \.order_by(Task.due_date).all()# 获取最近添加的任务recent_tasks = Task.query.filter_by(user_id=current_user.id) \.order_by(Task.created_at.desc()).limit(5).all()# 获取分类统计categories = Category.query.filter_by(user_id=current_user.id).all()category_stats = []for category in categories:total = Task.query.filter_by(user_id=current_user.id, category_id=category.id).count()completed = Task.query.filter_by(user_id=current_user.id, category_id=category.id, completed=True).count()if total > 0:completion_rate = (completed / total) * 100else:completion_rate = 0category_stats.append({'category': category,'total': total,'completed': completed,'completion_rate': completion_rate})return render_template('dashboard.html', total_tasks=total_tasks,completed_tasks=completed_tasks,pending_tasks=pending_tasks,due_soon_tasks=due_soon_tasks,overdue_tasks=overdue_tasks,recent_tasks=recent_tasks,category_stats=category_stats)@main.route('/tasks')
@login_required
def tasks():# 获取过滤参数status = request.args.get('status', '')category = request.args.get('category', '')priority = request.args.get('priority', '')sort = request.args.get('sort', 'due_date')order = request.args.get('order', 'asc')# 构建查询query = Task.query.filter_by(user_id=current_user.id)if status == 'completed':query = query.filter_by(completed=True)elif status == 'pending':query = query.filter_by(completed=False)if category and category != 'all':query = query.filter_by(category_id=category)if priority and priority != 'all':query = query.filter_by(priority=int(priority))# 排序if sort == 'due_date':if order == 'asc':query = query.order_by(Task.due_date.asc())else:query = query.order_by(Task.due_date.desc())elif sort == 'priority':if order == 'asc':query = query.order_by(Task.priority.asc())else:query = query.order_by(Task.priority.desc())elif sort == 'created_at':if order == 'asc':query = query.order_by(Task.created_at.asc())else:query = query.order_by(Task.created_at.desc())tasks = query.all()# 获取用户的分类categories = Category.query.filter_by(user_id=current_user.id).all()return render_template('tasks.html', tasks=tasks, categories=categories,status=status, category=category, priority=priority,sort=sort, order=order)@main.route('/task/add', methods=['GET', 'POST'])
@login_required
def add_task():categories = Category.query.filter_by(user_id=current_user.id).all()if request.method == 'POST':title = request.form['title']description = request.form.get('description', '')due_date_str = request.form.get('due_date', '')category_id = request.form.get('category', '')priority = request.form.get('priority', 1)if not title:flash('任务标题不能为空', 'error')return redirect(url_for('main.add_task'))due_date = Noneif due_date_str:try:due_date = datetime.strptime(due_date_str, '%Y-%m-%d')except ValueError:flash('日期格式不正确，请使用 YYYY-MM-DD 格式', 'error')return redirect(url_for('main.add_task'))task = Task(title=title,description=description,due_date=due_date,priority=priority,user_id=current_user.id,category_id=category_id if category_id else None)db.session.add(task)db.session.commit()flash('任务已添加', 'success')return redirect(url_for('main.tasks'))return render_template('task_form.html', categories=categories, is_edit=False)@main.route('/task/<int:task_id>/edit', methods=['GET', 'POST'])
@login_required
def edit_task(task_id):task = Task.query.get_or_404(task_id)# 确保用户只能编辑自己的任务if task.user_id != current_user.id:flash('权限不足', 'error')return redirect(url_for('main.tasks'))categories = Category.query.filter_by(user_id=current_user.id).all()if request.method == 'POST':task.title = request.form['title']task.description = request.form.get('description', '')due_date_str = request.form.get('due_date', '')task.category_id = request.form.get('category', '')task.priority = request.form.get('priority', 1)if not task.title:flash('任务标题不能为空', 'error')return redirect(url_for('main.edit_task', task_id=task_id))task.due_date = Noneif due_date_str:try:task.due_date = datetime.strptime(due_date_str, '%Y-%m-%d')except ValueError:flash('日期格式不正确，请使用 YYYY-MM-DD 格式', 'error')return redirect(url_for('main.edit_task', task_id=task_id))db.session.commit()flash('任务已更新', 'success')return redirect(url_for('main.tasks'))return render_template('task_form.html', task=task, categories=categories, is_edit=True)@main.route('/task/<int:task_id>/toggle', methods=['POST'])
@login_required
def toggle_task(task_id):task = Task.query.get_or_404(task_id)# 确保用户只能操作自己的任务if task.user_id != current_user.id:flash('权限不足', 'error')return redirect(url_for('main.tasks'))task.completed = not task.completeddb.session.commit()flash('任务状态已更新', 'success')return redirect(url_for('main.tasks'))@main.route('/task/<int:task_id>/delete', methods=['POST'])
@login_required
def delete_task(task_id):task = Task.query.get_or_404(task_id)# 确保用户只能删除自己的任务if task.user_id != current_user.id:flash('权限不足', 'error')return redirect(url_for('main.tasks'))db.session.delete(task)db.session.commit()flash('任务已删除', 'success')return redirect(url_for('main.tasks'))@main.route('/categories')
@login_required
def categories():categories = Category.query.filter_by(user_id=current_user.id).all()return render_template('categories.html', categories=categories)@main.route('/category/add', methods=['POST'])
@login_required
def add_category():name = request.form['name']if not name:flash('分类名称不能为空', 'error')return redirect(url_for('main.categories'))if Category.query.filter_by(user_id=current_user.id, name=name).first():flash('分类名称已存在', 'error')return redirect(url_for('main.categories'))category = Category(name=name, user_id=current_user.id)db.session.add(category)db.session.commit()flash('分类已添加', 'success')return redirect(url_for('main.categories'))@main.route('/category/<int:category_id>/edit', methods=['POST'])
@login_required
def edit_category(category_id):category = Category.query.get_or_404(category_id)# 确保用户只能编辑自己的分类if category.user_id != current_user.id:flash('权限不足', 'error')return redirect(url_for('main.categories'))name = request.form['name']if not name:flash('分类名称不能为空', 'error')return redirect(url_for('main.categories'))if Category.query.filter_by(user_id=current_user.id, name=name).first() and name != category.name:flash('分类名称已存在', 'error')return redirect(url_for('main.categories'))category.name = namedb.session.commit()flash('分类已更新', 'success')return redirect(url_for('main.categories'))@main.route('/category/<int:category_id>/delete', methods=['POST'])
@login_required
def delete_category(category_id):category = Category.query.get_or_404(category_id)# 确保用户只能删除自己的分类if category.user_id != current_user.id:flash('权限不足', 'error')return redirect(url_for('main.categories'))# 检查是否有任务属于该分类if Task.query.filter_by(user_id=current_user.id, category_id=category_id).count() > 0:flash('该分类下有任务，不能删除', 'error')return redirect(url_for('main.categories'))db.session.delete(category)db.session.commit()flash('分类已删除', 'success')return redirect(url_for('main.categories'))@main.route('/analytics')
@login_required
def analytics():# 获取任务统计数据total_tasks = Task.query.filter_by(user_id=current_user.id).count()completed_tasks = Task.query.filter_by(user_id=current_user.id, completed=True).count()pending_tasks = total_tasks - completed_tasks# 按优先级统计priority_stats = {}for priority in [1, 2, 3]:total = Task.query.filter_by(user_id=current_user.id, priority=priority).count()completed = Task.query.filter_by(user_id=current_user.id, priority=priority, completed=True).count()pending_tasks = total - completedif total > 0:completion_rate = (completed / total) * 100else:completion_rate = 0priority_stats[priority] = {'total': total,'completed': completed,'pending': pending_tasks,'completion_rate': completion_rate}# 按分类统计categories = Category.query.filter_by(user_id=current_user.id).all()category_stats = []for category in categories:total = Task.query.filter_by(user_id=current_user.id, category_id=category.id).count()completed = Task.query.filter_by(user_id=current_user.id, category_id=category.id, completed=True).count()if total > 0:completion_rate = (completed / total) * 100else:completion_rate = 0category_stats.append({'category': category,'total': total,'completed': completed,'completion_rate': completion_rate})# 最近7天的任务完成情况today = datetime.now().date()last_7_days = [(today - timedelta(days=i)) for i in range(6, -1, -1)]daily_stats = []for day in last_7_days:start_time = datetime.combine(day, datetime.min.time())end_time = datetime.combine(day, datetime.max.time())created = Task.query.filter_by(user_id=current_user.id) \.filter(Task.created_at.between(start_time, end_time)).count()completed = Task.query.filter_by(user_id=current_user.id, completed=True) \.filter(Task.due_date.between(start_time, end_time)).count()daily_stats.append({'date': day,'created': created,'completed': completed})return render_template('analytics.html', total_tasks=total_tasks,completed_tasks=completed_tasks,pending_tasks=pending_tasks,priority_stats=priority_stats,category_stats=category_stats,daily_stats=daily_stats)# 注册蓝图
app.register_blueprint(main)
app.register_blueprint(auth)# 创建数据库表
with app.app_context():db.create_all()if __name__ == '__main__':app.run(debug=True)