Support RPDO / TPDO lookup by communication parameter record index.

This does not work for the generic, joined accessor class PDO yet.

Author: acolomb

canopen/pdo/base.py

@@ -46,8 +46,7 @@ def __getitem__(self, key: Union[int, str]):
                 raise KeyError("PDO index zero requested for 1-based sequence")
             if (
                 0 < key <= 512  # By PDO Index
-                or 0x1600 <= key <= 0x17FF  # By RPDO ID (512)
-                or 0x1A00 <= key <= 0x1BFF  # By TPDO ID (512)
+                or 0x1600 <= key <= 0x1BFF  # By RPDO / TPDO mapping or communication record
             ):
                 return self.map[key]
         for pdo_map in self.map.values():
@@ -178,6 +177,8 @@ def __getitem__(self, key: int) -> PdoMap:
         except KeyError:
             with contextlib.suppress(KeyError):
                 return self.maps[key + 1 - self.map_offset]
+            with contextlib.suppress(KeyError):
+                return self.maps[key + 1 - self.com_offset]
             raise
 
     def __iter__(self) -> Iterator[int]:

test/test_pdo.py

@@ -54,6 +54,7 @@ def test_pdo_getitem(self):
         self.assertIsInstance(by_mapping_record, canopen.pdo.PdoMap)
         self.assertEqual(by_mapping_record['INTEGER16 value'].raw, -3)
         self.assertIs(node.tpdo[0x1A00], by_mapping_record)
+        self.assertIs(node.tpdo[0x1800], by_mapping_record)
         by_object_name = node.pdo['INTEGER16 value']
         self.assertIsInstance(by_object_name, canopen.pdo.PdoVariable)
         self.assertIs(by_object_name.od, node.object_dictionary['INTEGER16 value'])