Port test_issue_1974 from SLI to Py

testsuite/pytests/sli2py_mpi/test_issue_1974.py

@@ -0,0 +1,50 @@
+# -*- coding: utf-8 -*-
+#
+# test_issue_1974.py
+#
+# This file is part of NEST.
+#
+# Copyright (C) 2004 The NEST Initiative
+#
+# NEST is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 2 of the License, or
+# (at your option) any later version.
+#
+# NEST is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with NEST.  If not, see <http://www.gnu.org/licenses/>.
+
+
+from mpi_test_wrapper import MPITestAssertEqual
+
+
+@MPITestAssertEqual([1, 2, 4], debug=True)
+def test_issue_1974():
+    """
+    For each of the two parrot neurons, exactly one connection from/to the in/out MUSIC proxy must be created,
+    specifically to the proxy on the rank on which the parrot neuron exists. Therefore, the pooled connections across
+    ranks must be identical independent of number of ranks.
+    """
+
+    import nest
+
+    if not nest.ll_api.sli_func("statusdict/have_music ::"):
+        return
+
+    nest.total_num_virtual_procs = 4
+
+    nrns = nest.Create("parrot_neuron", 2)
+
+    music_in = nest.Create("music_event_in_proxy", 1, {"port_name": "in_spikes"})
+    music_out = nest.Create("music_event_out_proxy", 1, {"port_name": "out_spikes"})
+
+    nest.Connect(music_in, nrns)
+    nest.Connect(nrns, music_out)
+
+    conns = nest.GetConnections().get(output="pandas").drop(labels=["port"], axis=1)
+    conns.to_csv(OTHER_LABEL.format(nest.num_processes, nest.Rank()), index=False)  # noqa: F821