Dump Objects to JSON
Serialize single items and collections.
Dump Objects to JSON is a free Flask Academy lesson on CoddyKit — lesson 3 of 4. You can read the complete lesson below for free — then practise it hands-on in the browser with a built-in code editor and a 24/7 AI tutor. It is part of the Flask Academy learning path, one of 4 lessons in the course, and your progress syncs across the web and the CoddyKit app.
Dumping Defined
Turning a model object into plain JSON-ready data is called dumping. The schema reads your object and emits a clean dict.
Call dump
Pass your object to the schema's dump method. It returns a dictionary containing only the fields you declared, properly typed.
result = user_schema.dump(user)A Plain Dict Comes Back
The output of dump is an ordinary Python dict, not JSON text yet. That dict is exactly what jsonify happily turns into a response.
Pair with jsonify
Hand the dumped dict to Flask's jsonify to get a real response with the right content type and proper formatting.
return jsonify(user_schema.dump(user))Serialize Many at Once
Have a list of objects? Create the schema with many=True and dump returns a list of dicts in one tidy call.
UserSchema(many=True).dump(users)Reuse with the many Flag
You can also pass many=True straight to dump on an existing instance, so one schema serves both single and list endpoints.
user_schema.dump(users, many=True)Nested Objects Flow Through
Declare a Nested field and dump walks into related objects too. One call serializes a user and all of their posts together.
posts = fields.Nested(PostSchema, many=True)Dates Format Themselves
Because you used a DateTime field, dump renders it as an ISO string with no extra work. Consistent timestamps come for free.
Only Declared Fields Appear
Dump ignores anything not in the schema. Internal attributes like password_hash simply never show up, so your output stays safe.
Dump Never Validates
Remember that dump trusts your objects and does no validation. It is purely about output; checking input is the job of load.
A Complete View
Put it together: query the model, dump it, jsonify it, return it. That short pipeline replaces all those fragile hand-built dicts.
return jsonify(schema.dump(query_result))Quick Check
You need to serialize a list of user objects.
Recap
Use dump to turn objects into JSON-ready dicts, add many=True for lists, and let Nested fields handle relations. Then jsonify and return.
Frequently asked questions
Is the “Dump Objects to JSON” lesson free?
Yes — the full text of “Dump Objects to JSON” is free to read here on the web, and the Flask Academy course includes 4 lessons in total. To practise it interactively (a built-in code editor and a 24/7 AI tutor) and unlock the rest of the Flask Academy course, upgrade to CoddyKit PRO.
What will I learn in “Dump Objects to JSON”?
Serialize single items and collections. You practise Flask Academy with hands-on code you run directly in the browser, and a 24/7 AI tutor answers your questions as you work through the lesson.
Do I need any experience to start Flask Academy?
No prior experience is required. Flask Academy on CoddyKit is structured for beginners through advanced learners; this is — lesson 3 of 4, so you can start here or from the beginning and move at your own pace.
How long does the “Dump Objects to JSON” lesson take?
Most CoddyKit lessons take about 5–10 minutes. Each one is bite-sized and interactive, so you make steady progress and pick up exactly where you left off across the web and the app.
Can I write and run code in this Flask Academy lesson?
Yes. Every Flask Academy lesson includes a built-in code editor, so you write and run real code right in your browser and get instant AI feedback — no local setup required.