xbus-502-rest-example-2.py

#!/usr/bin/env python
"""
Model answer for REST workshop using OpenCalais
"""
##########################################################################
## Imports
##########################################################################

import requests


##########################################################################
## Module Variables/Constants
##########################################################################

DOJ_RELEASES_URL = 'http://www.justice.gov/api/v1/press_releases.json?pagesize=5'
OPEN_CALAIS_SERVICE_URL = 'http://api.opencalais.com/tag/rs/enrich'
OPEN_CALAIS_KEY = 'ADD_API_KEY_HERE'


##########################################################################
## Functions
##########################################################################

def fetch_press_releases():
    """
    Performs a GET on the DOJ web service and return the array found in the
    'results' attribute of the JSON response
    """
    # execute a GET request and store the results
    response = requests.get(DOJ_RELEASES_URL)

    # decode as json and store the results
    data = response.json()

    # return the 'results' array of press releases
    return data['results']


def fetch_semantic_entities(content):
    """
    Performs a POST on the Open Calais service using the supplied text and
    then returns the decoded response as a dict.
    """
    # setup a dict to hold the header values
    headers = {
        'x-calais-licenseID': OPEN_CALAIS_KEY,
        'accept': 'application/json',
        'content-type' : 'TEXT/HTML'
    }

    # ensure the content is encoded for utf-8
    encoded_content = content.encode('utf-8')

    # execute a POST to the Open Calais service
    response = requests.post(OPEN_CALAIS_SERVICE_URL,
        data=encoded_content, headers=headers)

    # decode as json and return a dict
    return response.json()


def print_entities(data):
    """
    Iterates through a dict and prints out the Type and Name of an
    entity if the appropriate attributes were found.
    """
    for key,value in data.iteritems():
        if '_typeGroup' in value and value['_typeGroup'] == 'entities':
            print '%s: %s' % (value['_type'], value['name'])


def main():
    """
    Main execution function to perform required actions
    """
    # fetch array of press releases
    press_releases = fetch_press_releases()

    # iterate press releases
    for release in press_releases:

        # fetch entities using Open Calais API
        entities = fetch_semantic_entities(release['body'])

        # print the title and entities found
        print '\n' + release['title']
        print_entities(entities)


##########################################################################
## Execution
##########################################################################

if __name__ == '__main__':
    main()