Add map access feature for lists

yangson/instance.py

@@ -196,12 +196,21 @@ def __getitem__(self, key: InstanceKey) -> "InstanceNode":
                 `name`.
             InstanceValueError: If the receiver's value is not an object.
         """
+        if isinstance(self.value, ArrayValue) and isinstance(key, tuple):
+            return self._mapentry(key)
+        if isinstance(self.value, ArrayValue) and isinstance(key, dict):
+            return self._mapentry(self._map2tuple(key))
         if isinstance(self.value, ObjectValue):
             return self._member(key)
         if isinstance(self.value, ArrayValue):
             return self._entry(key)
         raise InstanceValueError(self.json_pointer(), "scalar instance")
 
+    def __contains__(self, key: InstanceKey) -> bool:
+        """Checks if key does exist
+        """
+        return self.get(key) is not None
+
     def __iter__(self):
         """Return receiver's iterator.
 
@@ -223,6 +232,14 @@ def ita():
             return iter(self._member_names())
         raise InstanceValueError(self.json_pointer(), "scalar instance")
 
+    def get(self, key: InstanceKey, d=None):
+        """Return member or entry with given key, returns default if it does not exist
+        """
+        try:
+            return self[key]
+        except (InstanceValueError, NonexistentInstance):
+            return d
+
     def is_internal(self) -> bool:
         """Return ``True`` if the receiver is an instance of an internal node.
         """
@@ -491,6 +508,24 @@ def _entry(self, index: int) -> "ArrayEntry":
         except (IndexError, TypeError):
             raise NonexistentInstance(self.json_pointer(), "entry " + str(index)) from None
 
+    def _map2tuple(self, key: dict) -> tuple:
+        """generate tuple for key"""
+        keylist = []
+        for keyit in self.schema_node._key_members:
+            keylist.append(key[keyit])
+
+        return tuple(keylist)
+
+    def _mapentry(self, key: tuple) -> "ArrayEntry":
+        """iterate over all childs"""
+        for child in self:
+            """generate tuple for key"""
+            childkey = tuple(child[singlekey].value for singlekey in self.schema_node._key_members)
+            if key == childkey:
+                return child
+
+        raise NonexistentInstance(self.json_pointer(), f"key '{key}'") from None
+
     def _peek_schema_route(self, sroute: SchemaRoute) -> Value:
         irt = InstanceRoute()
         sn = self.schema_node

yangson/instvalue.py

@@ -35,7 +35,7 @@
 EntryValue = Union[ScalarValue, "ObjectValue"]
 """Type of the value a list ot leaf-list entry."""
 
-InstanceKey = Union[InstanceName, int]
+InstanceKey = Union[InstanceName, int, tuple, dict]
 """Index of an array entry or name of an object member."""
 
 MetadataObject = Dict[PrefName, ScalarValue]