flask.json

Serialize an object to a string of JSON.

Takes the same arguments as the built-in json.dumps, with some defaults from application configuration.

Serialize an object to JSON written to a file object.

Takes the same arguments as the built-in json.dump, with some defaults from application configuration.

Deserialize an object from a string of JSON.

Takes the same arguments as the built-in json.loads, with some defaults from application configuration.

Deserialize an object from JSON read from a file object.

Takes the same arguments as the built-in json.load, with some defaults from application configuration.

Serialize data to JSON and wrap it in a ~flask.Response with the :mimetype:`application/json` mimetype.

Uses dumps to serialize the data, but args and kwargs are treated as data rather than arguments to json.dumps.

1. Single argument: Treated as a single value.
2. Multiple arguments: Treated as a list of values. jsonify(1, 2, 3) is the same as jsonify([1, 2, 3]).
3. Keyword arguments: Treated as a dict of values. jsonify(data=data, errors=errors) is the same as jsonify({"data": data, "errors": errors}).
4. Passing both arguments and keyword arguments is not allowed as it's not clear what should happen.

from flask import jsonify

@app.route("/users/me")
def get_current_user():
    return jsonify(
        username=g.user.username,
        email=g.user.email,
        id=g.user.id,
    )

Will return a JSON response like this:

{
  "username": "admin",
  "email": "admin@localhost",
  "id": 42
}

The default output omits indents and spaces after separators. In debug mode or if JSONIFY_PRETTYPRINT_REGULAR is True, the output will be formatted to be easier to read.