add a way to clone/update a profile

aholmberg · aholmberg · commit 2469be41e3c9 · 2016-06-09T13:07:10.000-05:00
PYTHON-569
diff --git a/cassandra/cluster.py b/cassandra/cluster.py
@@ -21,6 +21,7 @@
 import atexit
 from collections import defaultdict, Mapping
 from concurrent.futures import ThreadPoolExecutor, wait as wait_futures
+from copy import copy
 import logging
 from random import random
 import socket
@@ -2062,6 +2063,21 @@ def _get_execution_profile(self, ep):
         except KeyError:
             raise ValueError("Invalid execution_profile: '%s'; valid profiles are %s" % (ep, profiles.keys()))
 
+    def execution_profile_clone_update(self, ep, **kwargs):
+        """
+        Returns a clone of the ``ep`` profile.  ``kwargs`` can be specified to update attributes
+        of the returned profile.
+
+        This is a shollow clone, so any objects referenced by the profile are shared. This means Load Balancing Policy
+        is maintained by inclusion in the active profiles. It also means updating any other rich objects will be seen
+        by the active profile. In cases where this is not desirable, be sure to replace the instance instead of manipulating
+        the shared object.
+        """
+        clone = copy(self._get_execution_profile(ep))
+        for attr, value in kwargs.items():
+            setattr(clone, attr, value)
+        return clone
+
     def prepare(self, query, custom_payload=None):
         """
         Prepares a query string, returning a :class:`~cassandra.query.PreparedStatement`
diff --git a/docs/api/cassandra/cluster.rst b/docs/api/cassandra/cluster.rst
@@ -146,6 +146,8 @@
 
    .. automethod:: set_keyspace(keyspace)
 
+   .. automethod:: execution_profile_clone_update
+
 .. autoclass:: ResponseFuture ()
 
    .. autoattribute:: query
