How to convert JSON response to Python dictionary?

Product Support
1

I’m working on integrating Facebook’s Authentication for user registration on my site, and I’ve encountered a problem when trying to convert a JSON response string into a Python dictionary. After getting my access token, I make a request to:

https://graph.facebook.com/me?access_token=MY_ACCESS_TOKEN

I get a JSON string like this:

{
    "id": "123456789",
    "name": "John Doe",
    "first_name": "John",
    "last_name": "Doe",
    "link": "http:\/\/www.facebook.com\/jdoe",
    "gender": "male",
    "email": "jdoe\u0040gmail.com",
    "timezone": -7,
    "locale": "en_US",
    "verified": true,
    "updated_time": "2011-01-12T02:43:35+0000"
}

I thought I could easily convert this string to a dictionary using something like dict(string), but I’m encountering the following error:

ValueError: dictionary update sequence element #0 has length 1; 2 is required

I also tried using Pickle, but that resulted in a KeyError: '{', and attempts with django.serializers also failed.

Can anyone help clarify how to properly convert this JSON string to a Python dictionary?

2

Ah, this data is in JSON format! If you’re using Python 2.6 or later, the built-in json module is your go-to for converting it into a Python dictionary. Back in the day, when Python was still on earlier versions, we had to rely on the third-party simplejson module for this.

Here’s how you can do it:

import json  # or `import simplejson as json` if you're on Python < 2.6  

json_string = u'{ "id":"123456789", ... }'  
obj = json.loads(json_string)  # obj will now contain a dictionary with the data

This method is straightforward and reliable—just what you need when dealing with JSON data.

3

That’s a great explanation! For well-formed JSON strings, there’s another way you can safely convert them to a Python dictionary using ast.literal_eval. It’s particularly useful when you want a secure way to evaluate strings containing Python literals.

Here’s an example:

import ast  

json_string = u'{ "id":"123456789", ... }'  
obj = ast.literal_eval(json_string)  # Safely converts the string to a dictionary

This is a bit more niche, but it comes in handy when the data might not always be pure JSON and needs some Python literal handling.

4

Adding to the above, if you’re fetching JSON data via an HTTP request, the requests library is a lifesaver. It has a json() method that directly converts the response into a Python dictionary.

Here’s how:

import requests  

response = requests.get('https://graph.facebook.com/me?access_token=MY_ACCESS_TOKEN')  
obj = response.json()  # Converts the JSON response to a dictionary

While all the methods mentioned earlier work well for converting JSON strings, the json.loads method stands out as the most straightforward approach when dealing directly with JSON data.