Improve example and sorting of docs for token

Author: singhpratyush

Diff for: example_1.py

@@ -2,6 +2,6 @@
 
 my_index = index.Index()
 
-my_index.index('1', 'hello, my world! going to work :(')
+my_index.index('1', 'hello, my world! going to work world! :(')
 my_index.index('2', 'bye bye world, going to sleep :)')
-print(my_index)
+print(my_index.get_docs_for_token('world'))

Diff for: index/__init__.py

@@ -1,3 +1,4 @@
+import operator
 import pickle
 
 from nltk.tokenize import RegexpTokenizer
@@ -73,6 +74,6 @@ def from_file(filename):
 
     def get_docs_for_token(self, token, count=None):
         docs = self._inverted_index[token]['frequency']
-        sorted_docs = sorted(docs.items(), key=lambda k, v: (v, k))
+        sorted_docs = sorted(docs.items(), key=operator.itemgetter(1), reverse=True)
         doc_list = list(sorted_docs)
         return doc_list if count is None else doc_list[:count]