Fix types

spynnaker/pyNN/models/neuron/population_machine_neurons.py

@@ -14,7 +14,8 @@
 from __future__ import annotations
 from collections.abc import Container
 import ctypes
-from typing import List, NamedTuple, Sequence, Set, Union, cast, TYPE_CHECKING
+from typing import (
+    List, NamedTuple, Sequence, Set, Union, Optional, cast, TYPE_CHECKING)
 
 import numpy
 
@@ -231,21 +232,22 @@ def _write_neuron_data_spec(
         self._neuron_data.write_data(
             spec, self._vertex_slice, self._neuron_regions)
 
-    def __find_default_key(self) -> int:
+    def __find_default_key(self) -> Optional[int]:
         routing_info = SpynnakerDataView.get_routing_infos()
         if not self._pop_vertex.extra_partitions:
             return routing_info.get_single_first_key_from_pre_vertex(
                 cast(AbstractVertex, self))
         partition_ids = set(
-            routing_info.get_partitions_outgoing_from_vertex(self))
+            routing_info.get_partitions_outgoing_from_vertex(
+                cast(AbstractVertex, self)))
         partition_ids = partition_ids - set(self._pop_vertex.extra_partitions)
         if len(partition_ids) > 1:
             raise ValueError(
                 "Multiple outgoing partitions found, cannot determine key")
         if len(partition_ids) == 0:
             return None
         return routing_info.get_safe_first_key_from_pre_vertex(
-            self, next(iter(partition_ids)))
+            cast(AbstractVertex, self), next(iter(partition_ids)))
 
     def _rewrite_neuron_data_spec(self, spec: DataSpecificationReloader):
         """

spynnaker/pyNN/models/neuron/synaptic_matrices.py

@@ -14,7 +14,7 @@
 from __future__ import annotations
 from dataclasses import dataclass
 from typing import (
-    Dict, List, NamedTuple, Optional, Sequence, Tuple, TYPE_CHECKING)
+    Dict, List, NamedTuple, Optional, Sequence, Tuple, TYPE_CHECKING, cast)
 
 import numpy
 from numpy import floating, uint32
@@ -40,6 +40,7 @@
     get_sdram_for_bit_field_region, get_bitfield_key_map_data,
     write_bitfield_init_data)
 from spynnaker.pyNN.models.common import PopulationApplicationVertex
+from spynnaker.pyNN.models.spike_source import SpikeSourcePoissonVertex
 
 from .synaptic_matrix_app import SynapticMatrixApp
 
@@ -549,7 +550,8 @@ def get_connections_from_machine(
         :rtype: list(~numpy.ndarray)
         """
         if self.__is_sdram_poisson_source(app_edge):
-            return app_edge.pre_vertex.read_connections(synapse_info)
+            return cast(SpikeSourcePoissonVertex, app_edge.pre_vertex)\
+                .read_connections(synapse_info)
         matrix = self.__matrices[app_edge, synapse_info]
         return matrix.get_connections(placement)