Flask 微框架

基本使用

from flask import Flask, jsonify, request

app = Flask(__name__)

@app.route('/')
def hello():
    return jsonify({"message": "Hello, Flask!"})

@app.route('/users/<int:user_id>')
def get_user(user_id):
    return jsonify({"id": user_id, "name": "Alice"})

if __name__ == '__main__':
    app.run(debug=True)

蓝图（Blueprint）

模块化组织路由：

auth.py

from flask import Blueprint

auth_bp = Blueprint('auth', __name__, url_prefix='/auth')

@auth_bp.route('/login', methods=['POST'])
def login():
    data = request.get_json()
    return jsonify({"token": "abc123"})

@auth_bp.route('/logout')
def logout():
    return jsonify({"message": "已登出"})

# app.py
app.register_blueprint(auth_bp)

常用扩展

扩展	用途
Flask-SQLAlchemy	ORM
Flask-Migrate	数据库迁移
Flask-Login	用户认证
Flask-WTF	表单处理
Flask-CORS	跨域处理
Flask-RESTful	REST API

示例：REST API

from flask import Flask, jsonify, request
from flask_sqlalchemy import SQLAlchemy

app = Flask(__name__)
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///app.db'
db = SQLAlchemy(app)

class User(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(80), nullable=False)

@app.route('/users', methods=['GET'])
def list_users():
    users = User.query.all()
    return jsonify([{"id": u.id, "name": u.name} for u in users])

@app.route('/users', methods=['POST'])
def create_user():
    data = request.get_json()
    user = User(name=data['name'])
    db.session.add(user)
    db.session.commit()
    return jsonify({"id": user.id, "name": user.name}), 201