Implementing Pagination in a Python 3.x REST API with Flask and SQLAlchemy
I'm optimizing some code but I'm working on a project and hit a roadblock. During development of an API for a project, I need to implement pagination to efficiently handle large datasets returned from a SQLAlchemy ORM. The API is built with Flask and I'm using Flask-RESTful to structure my endpoints. I want clients to specify how many records to return and the page number they wish to access. Here’s a snippet of what I’ve implemented so far: ```python from flask import Flask, request, jsonify from flask_sqlalchemy import SQLAlchemy app = Flask(__name__) app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///example.db' db = SQLAlchemy(app) class Item(db.Model): id = db.Column(db.Integer, primary_key=True) name = db.Column(db.String(80), nullable=False) @app.route('/items', methods=['GET']) def get_items(): page = request.args.get('page', 1, type=int) per_page = request.args.get('per_page', 10, type=int) items = Item.query.paginate(page, per_page, error_out=False) return jsonify({ 'items': [item.name for item in items.items], 'total': items.total, 'page': items.page, 'pages': items.pages }) ``` This basic setup works, but I’m running into challenges with the `paginate` method. Specifically, I want to ensure that if the requested page number exceeds the total number of pages, it should default back to the last available page instead of returning an empty list. So far, I've tried adding some additional logic after the pagination call: ```python if items.page > items.pages: items = Item.query.paginate(items.pages, per_page, error_out=False) ``` This approach seems to work, but it feels a bit clunky and could lead to performance issues if the dataset is extremely large. Is there a more elegant way to handle this scenario? Additionally, what's the best practice for returning appropriate HTTP status codes depending on the results? Should I return a `404 Not Found` if the page number exceeds the available pages, or is a `200 OK` with an empty items list sufficient? Would love to hear insights from others who have tackled pagination in a RESTful API context. My development environment is Linux. What's the best practice here? My development environment is Linux.