Add default to {Array,Object}Value constructor.

yangson/instvalue.py

 """This module contains classes andtype aliases representing instance values."""
 
 from datetime import datetime
-from typing import List, Union
+from typing import Dict, List, Union
 from .typealiases import *
 
 # Local type aliases
@@ -36,7 +36,7 @@ class StructuredValue:
 class ArrayValue(StructuredValue, list):
     """Array values corresponding to YANG lists and leaf-lists."""
 
-    def __init__(self, val: List[Value], ts: datetime=None):
+    def __init__(self, val: List[Value] = [], ts: datetime=None):
         StructuredValue.__init__(self, ts)
         list.__init__(self, val)
 
@@ -47,7 +47,8 @@ class ArrayValue(StructuredValue, list):
 class ObjectValue(StructuredValue, dict):
     """Array values corresponding to YANG container."""
 
-    def __init__(self, val: Dict[InstanceName, Value], ts: datetime = None):
+    def __init__(self, val: Dict[InstanceName, Value] = {},
+                 ts: datetime = None):
         StructuredValue.__init__(self, ts)
         dict.__init__(self, val)
 

yangson/schema.py

@@ -228,7 +228,7 @@ class InternalNode(SchemaNode):
 
     def default_value(self) -> Optional[ObjectValue]:
         """Return the receiver's default content."""
-        res = ObjectValue({})
+        res = ObjectValue()
         for c in self.default_children:
             dflt = c.default_value()
             if dflt is not None:
@@ -355,7 +355,7 @@ class InternalNode(SchemaNode):
 
         :param val: raw dictionary
         """
-        res = ObjectValue({})
+        res = ObjectValue()
         for qn in val:
             cn = self.iname2qname(qn)
             ch = self.get_data_child(*cn)
@@ -483,7 +483,7 @@ class SequenceNode(DataNode):
 
         :param val: raw array
         """
-        res = ArrayValue([])
+        res = ArrayValue()
         for en in val:
             res.append(self.entry_from_raw(en))
         return res