Add lab 2 implementation for TF-IDF ranking

Author: singhpratyush

lab_2.py

@@ -0,0 +1,22 @@
+import sys
+
+from index import Index
+from ranking.tf_idf_ranker import TfIdfRanker
+
+
+def main():
+    file = sys.argv[1]
+    print('Loading index from %s' % file)
+    index = Index.from_file(file)
+    while True:
+        try:
+            query = input('Enter query: ')
+            documents = TfIdfRanker.search(index, query)
+            for doc, score in documents:
+                print('%s : %s' % (doc, score))
+        except KeyboardInterrupt:
+            break
+
+
+if __name__ == '__main__':
+    main()