Support display no docstring

So far an empty docstring was shown when no docstring was specified. The
logic for displaying the docstring is in the package widget-code-input
and needed to be updatet to support no docstring.

pyproject.toml

@@ -30,7 +30,7 @@ classifiers = [
 dependencies = [
   "ipywidgets>=8.0.0",
   "numpy<2.0.0",
-  "widget_code_input>=4.0.13",
+  "widget_code_input @ git+https://github.com/agoscinski/widget-code-input@remove-docstring",
   "matplotlib",
   "termcolor"
 ]

src/scwidgets/code/_widget_code_input.py

@@ -71,7 +71,6 @@ def __init__(
         if function_name is None:
             raise ValueError("function_name must be given if no function is given.")
         function_parameters = "" if function_parameters is None else function_parameters
-        docstring = "\n" if docstring is None else docstring
         function_body = "" if function_body is None else function_body
         self._builtins = {} if builtins is None else builtins
         super().__init__(
@@ -152,9 +151,9 @@ def function_parameters_name(self) -> List[str]:
         return self.function_parameters.replace(",", "").split(" ")
 
     @staticmethod
-    def get_docstring(function: types.FunctionType) -> str:
+    def get_docstring(function: types.FunctionType) -> str | None:
         docstring = function.__doc__
-        return "" if docstring is None else textwrap.dedent(docstring)
+        return None if docstring is None else textwrap.dedent(docstring)
 
     @staticmethod
     def _get_function_source_and_def(

tests/test_code.py

@@ -69,6 +69,9 @@ def test_get_function_paramaters(self):
         assert CodeInput.get_function_parameters(self.mock_function_7) == "x, **kwargs"
 
     def test_get_docstring(self):
+        assert (
+            CodeInput.get_docstring(self.mock_function_0) is None
+        )
         assert (
             CodeInput.get_docstring(self.mock_function_1)
             == "\nThis is an example function.\nIt adds two numbers.\n"