Fix % in docstrings, version bump

dcargs/_arguments.py

@@ -357,6 +357,9 @@ def _generate_helptext(arg: ArgumentDefinition) -> _ArgumentTransformOutput:
             arg.parent_class, arg.field.name
         )
         if docstring_help is not None:
+            # Note that the percent symbol needs some extra handling in argparse.
+            # https://stackoverflow.com/questions/21168120/python-argparse-errors-with-in-help-string
+            docstring_help = docstring_help.replace("%", "%%")
             help_parts.append(docstring_help)
 
         if arg.default is not None and hasattr(arg.default, "name"):

setup.py

@@ -5,7 +5,7 @@
 
 setup(
     name="dcargs",
-    version="0.0.9",
+    version="0.0.10",
     description="Portable, reusable, strongly typed CLIs from dataclass definitions",
     long_description=long_description,
     long_description_content_type="text/markdown",

tests/test_docstrings.py

@@ -80,16 +80,19 @@ class HelptextHardString:
         x: str = (
             "This docstring may be tougher to parse!"
         )
-        """Helptext."""
+        """Helptext. 2% milk."""
         # fmt: on
 
+    # Note that the percent symbol needs some extra handling in argparse.
+    # https://stackoverflow.com/questions/21168120/python-argparse-errors-with-in-help-string
+
     f = io.StringIO()
     with pytest.raises(SystemExit):
         with contextlib.redirect_stdout(f):
             dcargs.parse(HelptextHardString, args=["--help"])
     helptext = f.getvalue()
     assert (
-        "--x STR     Helptext. (default: This docstring may be tougher to parse!)\n"
+        "--x STR     Helptext. 2% milk. (default: This docstring may be tougher to parse!)\n"
         in helptext
     )