Add support for 'scan' queries (#108)

pydruid/query.py

@@ -179,6 +179,10 @@ def export_pandas(self):
                 nres = []
                 for item in self.result:
                     nres += [e.get('event') for e in item['result'].get('events')]
+            elif self.query_type == "scan":
+                nres = []
+                for item in self.result:
+                    nres += [e for e in item.get('events')]
             else:
                 raise NotImplementedError(
                     'Pandas export not implemented for query '
@@ -423,3 +427,20 @@ def search(self, args):
         ]
         self.validate_query(query_type, valid_parts, args)
         return self.build_query(query_type, args)
+
+    def scan(self, args):
+        """
+        A scan query returns raw Druid rows
+
+        :param dict args: dict of args
+
+        :return: select query
+        :rtype: Query
+        """
+        query_type = 'scan'
+        valid_parts = [
+            'datasource', 'granularity', 'filter', 'dimensions', 'metrics',
+            'intervals', 'limit',
+        ]
+        self.validate_query(query_type, valid_parts, args)
+        return self.build_query(query_type, args)