The simplest way to encode JSON is with a dictionary. This basic dictionary holds random values of various datatypes.

data = {
    a: 0,
    b: 9.6,
    c: "Hello World",
    d: {
        a: 4
    }
}

We then use json.dumps() to convert the dictionary to a JSON object.

import json

data = {
    a: 0,
    b: 9.6,
    c: "Hello World",
    d: {
        a: 4
    }
}

json_data = json.dumps(data)
print(json_data)

This will print out

{"c": "Hello World", "b": 9.6, "d": {"e": [89, 90]}, "a": 0}

Notice how the keys are not sorted by default, you would have to add the sort_keys=True argument to json.dumps() like so.

import json

data = {
    a: 0,
    b: 9.6,
    c: "Hello World",
    d: {
        a: 4
    }
}

json_data = json.dumps(data, sort_keys=True)
print(json_data)

Which would then output the sorted keys.

{"a": 0, "b": 9.6, "c": "Hello World", "d": {"e": [89, 90]}}

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An application programming interface (API) is a protocol intended to be used as an interface by software components to communicate with each other. It’s basically a set of programming instructions and standards for accessing a Web-based software application or Web tool. A software company (like Amazon, Google etc) releases its API to the public so that other software developers can design products that are powered by its service. For a more extended explanation on API, read this excellent article from howstuffworks.com.

Interact with an API using JSON

It is important to know that an API is a software-to-software interface, not a user interface. With APIs, applications talk to each other without any user knowledge or intervention. When we want to interact with an API in Python (like accessing web services), we get the responses in a form called JSON. To interact with JSON, we can use the json and simplejson modules. JSON (JavaScript Object Notation) is a compact, text based format for computers to exchange data and is once loaded into Python just like a dictionary. JSON data structures map directly to Python data types, which makes this a powerful tool for directly accessing data without having to write any XML parsing code.

How do I do this?

Let’s show how we can do this by using Twittes API. The first thing you have to do, is to find an URL to call the API. The next step is to import the modules that we need.

import json
import urllib2

# open the url and the screen name 
# (The screen name is the screen name of the user for whom to return results for)
url = "http://api.twitter.com/1/statuses/user_timeline.json?screen_name=python"

# this takes a python object and dumps it to a string which is a JSON
# representation of that object
data = json.load(urllib2.urlopen(url))

# print the result
print data

More Examples

Using the Youtube API

Using the Vimeo API

Using the Twitter API

Using the Delicious API

LastFM API

Amazon API

Google API

Sources

http://money.howstuffworks.com/business-communications/how-to-leverage-an-api-for-conferencing1.htm

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Request to an HTTP API is often just the URL with some query parameters.

API Response

The responses that we get from an API is data, that data can come in various
formats, with the most popular being XML and JSON.

Many HTTP APIs support multiple response formats, so that developers can choose
the one they’re more comfortable parsing.

Getting Started

To get started, lets create a simple data structure and put in some data.

First we import the json module into our program.

import json

# Create a data structure
data = [ { 'Hola':'Hello', 'Hoi':"Hello", 'noun':"hello" } ]

To print the data to screen, is as simple as:

print 'DATA:', (data)

When we print the Data as above, we will see the following output:

DATA: [{'noun': 'hello', 'Hola': 'Hello', 'Hoi': 'Hello'}]

JSON Functions

When you use JSON in Python, there are different function that we can make use of

Json Dumps

The json.dumps function takes a Python data structure and returns it as a JSON string.

json_encoded = json.dumps(data)

# print to screen

print json_encoded

OUTPUT:

[{"noun": "hello", "Hola": "Hello", "Hoi": "Hello"}]

Json Loads

The json.loads() function takes a JSON string and returns it as a Python data
structure.

decoded_data = json.loads(json_encoded)

# print to screen

print decoded_data

OUTPUT:

[{u'noun': u'hello', u'Hola': u'Hello', u'Hoi': u'Hello’}]

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In this post we will explain how you can parse JSON objects in Python.

Knowing how to parse JSON objects is useful when you want to access an API
from various web services that gives the response in JSON.

Getting Started

First thing you have to do, is to find an URL to call the API.

In my example, I will use the Twitter API.

Start with importing the modules that we need for the program.

import json
import urllib2

Open the URL and the screen name.

url = "http://api.twitter.com/1/statuses/user_timeline.json?screen_name=wordpress"

Print out the result

print data

Using the Twitter API to parse data

This is a very simple program, just to give you an idea of how it works.

#Importing modules
import json
import urllib2

# Open the URL and the screen name
url = "http://api.twitter.com/1/statuses/user_timeline.json?screen_name=wordpress"

# This takes a python object and dumps it to a string which is a JSON representation of that object
data = json.load(urllib2.urlopen(url))

#print the result
print data

If you are interested to see another example of how to use JSON in Python, please
have a look at the “IMDB Crawler” script.

To use the Twitter API, see the official documentation on Twitter.
https://dev.twitter.com/docs

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JSON (JavaScript Object Notation) is a compact, text based format for computers to exchange data. The official Internet media type for JSON is application/json, and the JSON filename extension is .json

JSON is built on two structures:

A collection of name/value pairs
An ordered list of values.

JSON take these forms: objects, array, value, string, number

Object

Unordered set of name/value pairs. Begins with { and ends with }. Each name is followed by : (colon) The name/value pairs are separated by , (comma).

Array

Ordered collection of values. Begins with [ and ends with ]. Values are separated by , (comma).

Value

Can be a string in double quotes, number, or true or false or null, or an object or an array.

String

A sequence of zero or more Unicode characters, wrapped in double quotes, using backslash escapes.

Number

Integer, long, float

The following example shows the JSON representation of an object that describes a person:

{
    "firstName": "John",
    "lastName": "Smith",
    "age": 25,
    "address": {
        "streetAddress": "21 2nd Street",
        "city": "New York",
        "state": "NY",
        "postalCode": "10021"
    },
    "phoneNumber": [
        {
            "type": "home",
            "number": "212 555-1234"
        },
        {
            "type": "fax",
            "number": "646 555-4567"
        }
    ]
}

JSON data structures map directly to Python data types, so this is a powerful tool for directly accessing data without having to write any XML parsing code. JSON is once loaded into Python just like a dictionary.

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