NewsDiffs

A website and framework that tracks changes in online news articles over time.

Original installation at newsdiffs.org. A product of the Knight Mozilla MIT news hackathon in June 2012. Authors: Eric Price ([email protected]), Greg Price ([email protected]), and Jennifer 8. Lee ([email protected])

This is free software under the MIT/Expat license; see LICENSE. The project's source code lives at http://github.com/ecprice/newsdiffs .

Requirements

You need to have installed on your local machine

• Git
• Python 2.6 or later
• Django and other Python libraries

On a Debian- or Ubuntu-based system, it may suffice (untested) to run

  $ sudo apt-get install git-core python-django python-django-south python-simplejson

On Mac OS, the easiest way may be to install pip: http://www.pip-installer.org/en/latest/installing.html and then

  $ pip install Django

Initial setup

  $ python website/manage.py syncdb && python website/manage.py migrate
  $ mkdir articles

Running NewsDiffs Locally

Do the initial setup above. Then to start the webserver for testing:

  $ python website/manage.py runserver

and visit http://localhost:8000/

Running the scraper

Do the initial setup above. You will also need additional Python libraries; on a Debian- or Ubuntu-based system, it may suffice (untested) to run

  $ sudo apt-get install python-bs4 python-beautifulsoup

on a Mac, you will want something like

 $ pip install beautifulsoup4
 $ pip install beautifulsoup
 $ pip install html5lib

Note that we need two versions of BeautifulSoup, both 3.2 and 4.0; some websites are parsed correctly in only one version.

Then run

  $ python website/manage.py scraper

This will populate the articles repository with a list of current news articles. This is a snapshot at a single time, so the website will not yet have any changes. To get changes, wait some time (say, 3 hours) and run 'python website/manage.py scraper' again. If any of the articles have changed in the intervening time, the website should display the associated changes.

The scraper will log progress to /tmp/newsdiffs_logging (which is overwritten each run) and errors to /tmp/newsdiffs/logging_errs (which is cumulative).

To run the scraper every hour, run something like:

 $ while true; do python website/manage.py scraper; sleep 60m; done

or make a cron job.

Adding new sites to the scraper

The procedure for adding new sites to the scraper is outlined in parsers/init.py . You need to

1. Create a new parser module in parsers/ . This should be a subclass of BaseParser (in parsers/baseparser.py). Model it off the other parsers in that directory. You can test the parser with by running, e.g.,

   $ python parsers/test_parser.py bbc.BBCParser
   

   which will output a list of URLs to track, and

   $ python parsers/test_parser.py bbc.BBCParser http://www.bbc.co.uk/news/uk-21649494
   

   which will output the text that NewsDiffs would store.

2. Add the parser to 'parsers' in parsers/init.py

This should cause the scraper to start tracking the site.

To make the source display properly on the website, you will need minor edits to two other files: website/frontend/models.py and website/frontend/views.py (to define the display name and create a tab for the source, respectively). Search for 'bbc' to find the locations to edit.

Note, if you get an error like:

UnicodeEncodeError: 'ascii' codec can't encode character ....

likely your python is miscofigured such that it is refusing to output utf8 to your terminal. This happens often on a mac. For a simple workaround, force python into UTF-8 mode by exporting the following:

export PYTHONIOENCODING=utf-8