CODEWITHSUNDEEP
pythonbottle
Mark Bell
Mark Bell

Reputation: 29775

How do I return a JSON array with Bottle?

I'm writing an API using Bottle, which so far has been fantastic. However, I've run up against a small hurdle when trying to return a JSON array. Here's my test app code:

from bottle import route, run

@route('/single')
def returnsingle():
    return { "id": 1, "name": "Test Item 1" }

@route('/containsarray')
def returncontainsarray():
    return { "items": [{ "id": 1, "name": "Test Item 1" }, { "id": 2, "name": "Test Item 2" }] }

@route('/array')
def returnarray():
    return [{ "id": 1, "name": "Test Item 1" }, { "id": 2, "name": "Test Item 2" }]

run(host='localhost', port=8080, debug=True, reloader=True)

When I run this and request each route, I get the JSON responses I'd expect from the first two routes:

/single

{ id: 1, name: "Test Item 1" }

/containsarray

{ "items": [ { "id": 1, "name": "Test Item 1" }, { "id": 2, "name": "Test Item 2" } ] }

So, I had expected returning a list of dictionaries to create the following JSON response:

[ { "id": 1, "name": "Test Object 1" }, { "id": 2, "name": "Test Object 2" } ]

But requesting the /array route just results in an error. What am I doing wrong, and how can I return a JSON array in this manner?

Upvotes: 38

Views: 39872

Answers (2)

Vinay Sajip
Vinay Sajip

Reputation: 99530

Bottle's JSON plugin expects only dicts to be returned - not arrays. There are vulnerabilities associated with returning JSON arrays - see for example this post about JSON hijacking.

If you really need to do this, it can be done, e.g.

@route('/array')
def returnarray():
    from bottle import response
    from json import dumps
    rv = [{ "id": 1, "name": "Test Item 1" }, { "id": 2, "name": "Test Item 2" }]
    response.content_type = 'application/json'
    return dumps(rv)

Upvotes: 82

jose.angel.jimenez
jose.angel.jimenez

Reputation: 2247

According to Bottle's 0.12 documentation:

As mentioned above, Python dictionaries (or subclasses thereof) are automatically transformed into JSON strings and returned to the browser with the Content-Type header set to application/json. This makes it easy to implement json-based APIs. Data formats other than json are supported too. See the tutorial-output-filter to learn more.

Which means you don't need to import json nor setting the content_type attribute of the response.

Thus, the code gets hugely reduced:

@route('/array')
def returnarray():
    rv = [{ "id": 1, "name": "Test Item 1" }, { "id": 2, "name": "Test Item 2" }]
    return dict(data=rv)

And the JSON document returned by the Web server would look like:

{"data": [{"id": 1, "name": "Test Item 1"}, {"id": 2, "name": "Test Item 2"}]}

Upvotes: 21

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