Update object_mapper.py

Author: tylertjburns

mapper/object_mapper.py

@@ -2,7 +2,7 @@
 """
 Copyright (C) 2015, marazt. All rights reserved.
 """
-from inspect import getmembers, isroutine
+from inspect import getmembers, isroutine, signature
 from datetime import date, datetime
 
 from mapper.casedict import CaseDict
@@ -166,10 +166,6 @@ def map(self, from_obj, to_type=type(None), ignore_case=False, allow_none=False,
                 .format(key_from.__module__, key_from.__name__, to_type.__module__, to_type.__name__))
             key_to = to_type
         custom_mappings = self.mappings[key_from][key_to][1]
-        
-        # Currently, all target class data members need to have default value
-        # Object with __init__ that carries required non-default arguments are not supported
-        inst = key_to()
 
         def not_private(s):
             return not s.startswith('_')
@@ -183,6 +179,12 @@ def is_included(s, mapping):
         from_obj_attributes = getmembers(from_obj, lambda a: not isroutine(a))
         from_obj_dict = {k: v for k, v in from_obj_attributes}
 
+        # support __init__ by passing arguments by keyword when instantiating the key_to
+        sig = signature(key_to.__init__)
+        kwargs = {x: from_obj_dict[x] for x in sig.parameters if x not in ('self', 'kwargs')}
+
+        inst = key_to(**kwargs)
+        
         to_obj_attributes = getmembers(inst, lambda a: not isroutine(a))
         to_obj_dict = {k: v for k, v in to_obj_attributes if not_excluded(k) and (not_private(k) or is_included(k, custom_mappings))}