fix: Unable to access nested list property

Author: arajkumar

flask_restplus/fields.py

@@ -42,6 +42,10 @@ def is_indexable_but_not_string(obj):
     return not hasattr(obj, "strip") and hasattr(obj, "__iter__")
 
 
+def is_integer_indexable(obj):
+    return isinstance(obj, list) or isinstance(obj, set)
+
+
 def get_value(key, obj, default=None):
     '''Helper for pulling a keyed value off various types of objects'''
     if isinstance(key, int):
@@ -66,6 +70,11 @@ def _get_value_for_key(key, obj, default):
             return obj[key]
         except (IndexError, TypeError, KeyError):
             pass
+    if is_integer_indexable(obj):
+        try:
+            return obj[int(key)]
+        except (IndexError, TypeError, ValueError):
+            pass
     return getattr(obj, key, default)
 
 

tests/test_fields.py

@@ -148,6 +148,14 @@ def test_with_attribute(self):
         field = fields.Raw(attribute='bar')
         assert field.output('foo', {'bar': 42}) == 42
 
+    def test_with_attribute_list(self):
+        field = fields.Raw(attribute='bar.0')
+        assert field.output('foo', {'bar': [42]}) == 42
+
+    def test_with_attribute_dict_list(self):
+        field = fields.Raw(attribute='bar.0.val')
+        assert field.output('foo', {'bar': [{'val': 42}]}) == 42
+
     def test_with_lambda_attribute(self, mocker):
         obj = mocker.Mock()
         obj.value = 42