Fix showing default value in documentation.

Affects `Get Fron Dictionary` and `Pop From Dictionery`. Fixes #5032.

atest/robot/libdoc/LibDocLib.py

@@ -67,13 +67,13 @@ def get_repr_from_arg_model(self, model):
         return str(ArgInfo(kind=model['kind'],
                            name=model['name'],
                            type=self._get_type_info(model['type']),
-                           default=model['default'] or NOT_SET))
+                           default=self._get_default(model['default'])))
 
     def get_repr_from_json_arg_model(self, model):
         return str(ArgInfo(kind=model['kind'],
                            name=model['name'],
                            type=self._get_type_info(model['type']),
-                           default=model['defaultValue'] or NOT_SET))
+                           default=self._get_default(model['defaultValue'])))
 
     def _get_type_info(self, data):
         if not data:
@@ -82,3 +82,6 @@ def _get_type_info(self, data):
             return TypeInfo.from_string(data)
         nested = [self._get_type_info(n) for n in data.get('nested', ())]
         return TypeInfo(data['name'], None, nested=nested or None)
+
+    def _get_default(self, data):
+        return data if data is not None else NOT_SET

atest/robot/libdoc/python_library.robot

@@ -135,3 +135,8 @@ Deprecation
     ...
     ...                                       RF and Libdoc don't consider this being deprecated.
     Keyword Should Not Be Deprecated     3
+
+NOT_SET as default value
+    Run Libdoc And Parse Output      Collections
+    Keyword Name Should Be           17    Get From Dictionary
+    Keyword Arguments Should Be      17    dictionary    key    default=

src/robot/libraries/Collections.py

@@ -18,12 +18,15 @@
 from itertools import chain
 
 from robot.api import logger
-from robot.utils import (get_error_message, is_dict_like, is_list_like, Matcher,
-                         NOT_SET, plural_or_not as s, seq2str, seq2str2, type_name)
+from robot.utils import (is_dict_like, is_list_like, Matcher, NotSet,
+                         plural_or_not as s, seq2str, seq2str2, type_name)
 from robot.utils.asserts import assert_equal
 from robot.version import get_version
 
 
+NOT_SET = NotSet()
+
+
 class _List:
 
     def convert_to_list(self, item):

src/robot/utils/__init__.py

@@ -54,7 +54,7 @@
 from .misc import (classproperty, isatty, parse_re_flags, plural_or_not,
                    printable_name, seq2str, seq2str2, test_or_task)
 from .normalizing import normalize, normalize_whitespace, NormalizedDict
-from .notset import NOT_SET
+from .notset import NOT_SET, NotSet
 from .platform import PY_VERSION, PYPY, UNIXY, WINDOWS, RERAISED_EXCEPTIONS
 from .recommendations import RecommendationFinder
 from .robotenv import get_env_var, set_env_var, del_env_var, get_env_vars

src/robot/utils/notset.py

@@ -19,8 +19,8 @@ class NotSet:
     Can be used instead of the standard ``None`` in cases where ``None``
     itself is a valid value.
 
-    Use the constant ``robot.utils.NOT_SET`` instead of creating new instances
-    of the class.
+    ``robot.utils.NOT_SET`` is an instance of this class, but it in same cases
+    it is better to create a separate instance.
 
     New in Robot Framework 7.0.
     """
@@ -30,4 +30,3 @@ def __repr__(self):
 
 
 NOT_SET = NotSet()
-