[NEST Users] CreateLayer problem with dictionary

Hello, I am having a basic problem creating layers with topology (pyhton 3.6 and NEST 2.20.1). It always complains about the dictionary sent to CreateLayer, telling it is a number. The code below correctly prints <class 'dict'> but prints this error: Traceback (most recent call last): File "test/binary_gdf.py", line 9, in <module> kk=tp.CreateLayer({'extent': [1, 1],'rows': 20, 'columns': 20,'elements' : 'izhikevich','edge_wrap':True}) File "/home/neurobit/local/nest-py3/lib64/python3.6/site-packages/nest/topology/hl_api.py", line 650, in CreateLayer return topology_func('{ CreateLayer } Map', specs) File "/home/neurobit/local/nest-py3/lib64/python3.6/site-packages/nest/topology/ll_api.py", line 61, in topology_func return nest.ll_api.sli_func(slifunc, *args) File "/home/neurobit/local/nest-py3/lib64/python3.6/site-packages/nest/ll_api.py", line 182, in sli_func sli_run(slifun) # SLI support code to execute s on args File "/home/neurobit/local/nest-py3/lib64/python3.6/site-packages/nest/ll_api.py", line 132, in catching_sli_run raise exceptionCls(commandname, message) nest.lib.hl_api_exceptions.TypeMismatch: ('TypeMismatch in CreateLayer_D: Expected datatype: doubletype\nProvided datatype: integertype', 'TypeMismatch', <SLILiteral: CreateLayer_D>, ': Expected datatype: doubletype\nProvided datatype: integertype') Any help would be nice :-) Xavier ---- import nest import nest.topology as tp nest.SetKernelStatus({"overwrite_files": True}) my_dict = {'extent': [1, 1],'rows': 20, 'columns': 20,'elements' : 'izhikevich','edge_wrap':True} print(type(my_dict)) kk=tp.CreateLayer(my_dict)