Create() does not work MPI-parallel with arrays of parameter values

.gitignore

@@ -75,3 +75,6 @@ cscope.out
 
 # Merge conflict artifacts
 *.orig
+
+# local test files
+local_tests/*

pynest/nest/lib/hl_api_nodes.py

@@ -146,7 +146,7 @@ def Create(model, n=1, params=None, positions=None):
 
     if params is not None and iterable_or_parameter_in_params:
         try:
-            SetStatus(node_ids, params)
+            node_ids.set(params)
         except Exception:
             warnings.warn(
                 "SetStatus() call failed, but nodes have already been "

pynest/nest/lib/hl_api_types.py

@@ -23,6 +23,7 @@
 Classes defining the different PyNEST types
 """
 
+import itertools
 import json
 import numbers
 from math import floor, log
@@ -468,6 +469,13 @@ def set(self, params=None, **kwargs):
 
         local_nodes = [self.local] if len(self) == 1 else self.local
 
+        all_nodes_ids = [self.get("global_id")] if len(self) == 1 else self.get("global_id")
+        only_local_nodes_ids = list(itertools.compress(all_nodes_ids, local_nodes))
+        selected_local_nodes = NodeCollection(only_local_nodes_ids)
+
+        if len(selected_local_nodes) == 0:
+            # No local nodes, nothing to do
+            return
         if isinstance(params, dict) and "compartments" in params:
             if isinstance(params["compartments"], Compartments):
                 params["compartments"] = params["compartments"].get_tuple()
@@ -482,15 +490,15 @@ def set(self, params=None, **kwargs):
                 # Adding receptors has been handled by the += operator, so we can remove the entry.
                 params.pop("receptors")
 
-        if isinstance(params, dict) and all(local_nodes):
-            node_params = self[0].get()
+        if isinstance(params, dict):
+            node_params = selected_local_nodes[0].get()
             contains_list = [
                 is_iterable(vals) and key in node_params and not is_iterable(node_params[key])
                 for key, vals in params.items()
             ]
 
             if any(contains_list):
-                temp_param = [{} for _ in range(self.__len__())]
+                temp_param = [{} for _ in range(len(selected_local_nodes))]
 
                 for key, vals in params.items():
                     if not is_iterable(vals):
@@ -501,10 +509,11 @@ def set(self, params=None, **kwargs):
                             temp_dict[key] = vals[i]
                 params = temp_param
 
-        if isinstance(params, (list, tuple)) and self.__len__() != len(params):
-            raise TypeError("status dict must be a dict, or a list of dicts of length {} ".format(self.__len__()))
+        if isinstance(params, (list, tuple)) and len(selected_local_nodes) != len(params):
+            n = len(selected_local_nodes)
+            raise TypeError("status dict must be a dict, or a list of dicts of length {} ".format(n))
 
-        sli_func("SetStatus", self._datum, params)
+        sli_func("SetStatus", selected_local_nodes._datum, params)
 
     def tolist(self):
         """