python3: fix itervalues

rhodecode/lib/rc_cache/utils.py

@@ -277,8 +277,7 b' class InvalidationContext(object):'
     """
 
     def __repr__(self):
-        return '<InvalidationContext:{}[{}]>'.format(
-            safe_str(self.cache_key), safe_str(self.uid))
+        return f'<InvalidationContext:{self.cache_key}[{self.uid}]>'
 
     def __init__(self, uid, invalidation_namespace='',
                  raise_exception=False, thread_scoped=None):
@@ -311,9 +310,10 b' class InvalidationContext(object):'
         cache_obj_map = CacheKey.get_namespace_map(invalidation_namespace)
         cache_obj = cache_obj_map.get(self.cache_key)
         log.debug('Fetched cache obj %s using %s cache key.', cache_obj, self.cache_key)
+
         if not cache_obj:
             new_cache_args = invalidation_namespace
-            first_cache_obj = next(cache_obj_map.itervalues()) if cache_obj_map else None
+            first_cache_obj = next(iter(cache_obj_map.values())) if cache_obj_map else None
             cache_state_uid = None
             if first_cache_obj:
                 cache_state_uid = first_cache_obj.cache_state_uid