Added a new example for generating networks from Twitter social graph…

… data

examples/generators/social_graph.py

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+#!/usr/bin/env python
+# encoding: utf-8
+"""
+social_graph.py
+
+Description: This is an example of how to interact with a restful wed-based API to build a 
+			 a network from social graph data.  In this case, we will use Google's SocialGraph
+			 API to build the local star-graph for a given Twitter user
+			
+# Copyright (c) 2011, under the Simplified BSD License.  
+# For more information on FreeBSD see: http://www.opensource.org/licenses/bsd-license.php
+# All rights reserved.
+"""
+
+__auhthor__= """Drew Conway (drew.conway@nyu.edu)"""
+__date__ = """2011-07-12"""
+__credits__ = """"""
+__revision__ = ""
+
+import networkx as nx
+import urllib2
+import json
+import re
+import warnings
+
+def socialGraphAPI(user):
+	"""Returns the raw, unparsed, JSON from a call to the Google SocialGraph API
+	for a given Twitter user. """
+
+	gsg_url = 'https://socialgraph.googleapis.com/lookup?q=http://twitter.com/'+user+"&edo=1&edi=1"
+	gsg_raw = urllib2.urlopen(gsg_url)
+	return gsg_raw.readlines()[0]
+
+def getSocialGraph(user):
+	"""
+	Returns the parsed JSON text from a call to the Google SocialGraph API
+	for a given Twitter user.
+	"""
+
+	# Get the raw JSON, and check that there was no HTTP error
+	gsg_json = socialGraphAPI(user)
+	while gsg_json.find("Service Unavailable. Please try again later.") > -1:
+		gsg_json = socialGraphAPI(user)
+	# Decode the JSON, and check that the user existed
+	return json.loads(gsg_json)
+
+def stripURL(twitter_url):
+	"""Return the user name from a given Twitter URL"""
+	return re.split('[/\.]', twitter_url)[-1]
+
+def buildSocialGraph(user, twitter_only=True):
+	"""Builds a NetworkX DiGraph object from a Twitter user's social graph"""
+
+	gsg_data = getSocialGraph(user)
+
+	nodes_out = gsg_data['nodes']['http://twitter.com/'+user]['nodes_referenced'].keys()
+	nodes_in = gsg_data['nodes']['http://twitter.com/'+user]['nodes_referenced_by'].keys()
+
+	# Check if any data was returned, and if not, issue warning
+	null_user = False
+	if len(nodes_out) < 1 and len(nodes_in) < 1:
+		warnings.warn("API call returned no data, check that '"+user+"' exists.\nReturning empty graph", UserWarning)
+		null_user = True
+
+	# Some of the nodes returned by GSG are not Twitter, but other social network website.  
+	# To build a graph from links to only Twitter pages set to True to search for only 
+	# nodes with 'http://twitter.com/'. This will also remove the 'http' heading around 
+	# a Twitter user.
+	if twitter_only and not null_user:
+		nodes_out = [(v) for (v) in nodes_out if v.find('http://twitter.com/') > -1 and v.find('/account/') < 0]
+		nodes_out = map(stripURL, nodes_out)	# Strips out only the user name
+		nodes_in = [(v) for (v) in nodes_in if v.find('http://twitter.com/') > -1 and v.find('/account/') < 0]
+		nodes_in = map(stripURL, nodes_in)
+
+	# Build the edge list and return the DiGraph
+	gsg_graph = nx.DiGraph()
+	if not null_user:
+		# To keep node labeling consistent in each case
+		if not twitter_only:
+			user = 'http://twitter.com/'+user
+
+		gsg_graph.add_edges_from(map(lambda i: (user, nodes_out[i]), xrange(len(nodes_out))))
+		gsg_graph.add_edges_from(map(lambda i: (nodes_in[i], user), xrange(len(nodes_in))))
+
+	gsg_graph.name = user
+	return gsg_graph
+
+def main():
+	test_user = 'hmason'
+	test_graph = buildSocialGraph(test_user, twitter_only=True)
+
+	print nx.info(test_graph)
+
+	"""
+	Additional problems:
+	
+		1: Define node types for all data returned from the API calls; including, Twitter users, 
+		   Twitter lists, non-Twitter nodes, or more.
+		
+		2. Write a function to generate a k-snowball search for a given seed users.  This would
+		   require taking users returned from buildSocialGraph and using them as new seeds.
+	"""
+
+if __name__ == '__main__':
+	main()
+