Add segment cat api

elasticsearch/client/cat.py

@@ -193,6 +193,25 @@ class CatClient(NamespacedClient):
             'shards', index), params=params)
         return data
 
+    @query_params('h', 'help', 'local', 'master_timeout', 'v')
+    def segments(self, index=None, params=None):
+        """
+        The segments command is the detailed view of Lucene segments per index.
+
+        :arg index: A comma-separated list of index names to limit the returned
+            information
+        :arg h: Comma-separated list of column names to display
+        :arg help: Return help information, default False
+        :arg local: Return local information, do not retrieve the state from
+            master node (default: false)
+        :arg master_timeout: Explicit operation timeout for connection to master
+            node
+        :arg v: Verbose mode. Display column headers, default False    
+        """
+        _, data = self.transport.perform_request('GET', _make_path('_cat',
+            'segments', index), params=params)
+        return data
+    
     @query_params('h', 'help', 'local', 'master_timeout', 'v')
     def pending_tasks(self, params=None):
         """