带范围的简单分页算法

from flask import Flask, request, jsonify
from sqlalchemy import create_engine, Column, Integer, String
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import sessionmaker

app = Flask(__name__)
engine = create_engine('sqlite:///example.db')
Base = declarative_base()
Session = sessionmaker(bind=engine)

class Item(Base):
    __tablename__ = 'items'
    id = Column(Integer, primary_key=True)
    name = Column(String)

Base.metadata.create_all(engine)

@app.route('/items')
def get_items():
    page = int(request.args.get('page', 1))
    per_page = int(request.args.get('per_page', 10))
    
    session = Session()
    total_items = session.query(Item).count()
    total_pages = (total_items + per_page - 1) // per_page
    
    items = session.query(Item).offset((page - 1) * per_page).limit(per_page).all()
    
    result = {
        'total_items': total_items,
        'total_pages': total_pages,
        'current_page': page,
        'items': [{'id': item.id, 'name': item.name} for item in items]
    }
    
    return jsonify(result)

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