Handling Date Formatting in JSON API Responses with Flask and Marshmallow
I'm updating my dependencies and I'm migrating some code and I've tried everything I can think of but I'm working on a project and hit a roadblock. I'm working on a Flask application using Marshmallow for serialization, and I'm working with an scenario with formatting date fields in my JSON API responses. Specifically, I'm trying to return a date in 'YYYY-MM-DD' format, but despite setting the format in my schema, the output is still in the default format, which includes time and timezone information. Here's a simplified version of my code: ```python from flask import Flask, jsonify from flask_marshmallow import Marshmallow from marshmallow import fields from datetime import datetime app = Flask(__name__) ma = Marshmallow(app) class EventSchema(ma.Schema): id = fields.Int(required=True) name = fields.Str(required=True) event_date = fields.Date(format='%Y-%m-%d') # Trying to set the date format here # Sample event data EVENT_DATA = [ { 'id': 1, 'name': 'Conference', 'event_date': datetime(2023, 10, 15, 14, 30) }, { 'id': 2, 'name': 'Workshop', 'event_date': datetime(2023, 11, 5, 9, 0) } ] @app.route('/events', methods=['GET']) def get_events(): schema = EventSchema(many=True) result = schema.dump(EVENT_DATA) return jsonify(result) if __name__ == '__main__': app.run(debug=True) ``` When I hit the `/events` endpoint, I get the following response: ```json [ {"id": 1, "name": "Conference", "event_date": "2023-10-15 14:30:00"}, {"id": 2, "name": "Workshop", "event_date": "2023-11-05 09:00:00"} ] ``` As you can see, the `event_date` is still including the time. I have tried adjusting the `format` parameter in the `fields.Date` definition, but it doesn't seem to have any effect. I've also checked the Marshmallow documentation and tried using `fields.DateTime` with a similar format, but I still end up with the same result. I'm using Flask 2.1.0 and Flask-Marshmallow 0.14.0. Any suggestions on how to enforce this date formatting in my JSON response? My development environment is Linux. Thanks in advance! The project is a mobile app built with Python. The stack includes Python and several other technologies. This is for a mobile app running on Ubuntu 22.04. I'm on Windows 10 using the latest version of Python. Any help would be greatly appreciated!