Fixed double shift implementation. Added implicit renaming

tests/test_default_data_presenter.py

@@ -14,6 +14,18 @@ def test_i_can_present_static_mappings():
   assert actual == Expando({"renamed_1": "value1", "field2": "value2"})  # field3 is removed
 
 
+def test_i_can_present_implicit_renaming():
+  mappings_def = "root.field1="
+  presenter = DefaultDataPresenter("comp_id", mappings_def)
+  as_dict = {"root": {"field1": "value1"}}
+  data = Expando(as_dict)
+  
+  actual = presenter.present(data)
+  
+  assert isinstance(actual, Expando)
+  assert actual.as_dict() == {"field1": "value1"}
+
+
 def test_the_latter_mappings_take_precedence():
   mappings_def = "field1 = renamed_1 , field1  "
   presenter = DefaultDataPresenter("comp_id", mappings_def)
@@ -105,6 +117,23 @@ def test_i_can_present_dynamic_mappings_with_sub_fields_and_renames():
                               "field4": "value4"}
 
 
+def test_i_can_present_dynamic_mappings_with_sub_fields_and_implicit_renames():
+  mappings_def = "root.sub_field.*="
+  presenter = DefaultDataPresenter("comp_id", mappings_def)
+  as_dict = {"root": {"field1": "value1",
+                      "field2": "value2",
+                      "sub_field": {"field3": "value3",
+                                    "field4": "value4"
+                                    }}}
+  data = Expando(as_dict)
+  
+  actual = presenter.present(data)
+  
+  assert isinstance(actual, Expando)
+  assert actual.as_dict() == {"field3": "value3",
+                              "field4": "value4"}
+
+
 def test_i_can_present_dynamic_mappings_and_rename_them():
   mappings_def = "*=*"  # does not really have effects as '*' only goes down one level
   presenter = DefaultDataPresenter("comp_id", mappings_def)