Work around passing arguments matching Python keywords

Author: kamilburda

CHANGELOG.md

@@ -7,6 +7,7 @@
 * Updated type annotations for parameters that can be `None` (e.g. `Gimp.Image` or `Gimp.Layer`) in the stub file.
 * Slightly optimized access to PDB procedures and GEGL operations via the `pdb` object.
 * Improved GUI for the output directory for the stub generator.
+* Arguments whose names match a Python keyword can now be passed with a trailing `_`, e.g. `lambda_` (passing `lambda=<value>` would result in a syntax error).
 
 
 4.2

generate-pdb-stubs/stubgen.py

@@ -2,6 +2,7 @@
 
 import ast
 import inspect
+import keyword
 import os
 import re
 import sys
@@ -161,7 +162,7 @@ def _insert_gimp_pdb_procedure_node(pypdb_class_node, procedure_name):
 
 
 def _create_pdb_procedure_node(procedure_name):
-  func_name = pypdb.pdb.canonical_name_to_python_name(procedure_name)
+  func_name = _canonical_name_to_python_name(procedure_name)
 
   # Constructing a `FunctionDef` node this way is more readable and less error-prone.
   func_base_arguments_str = 'self'
@@ -179,7 +180,7 @@ def _insert_gimp_pdb_procedure_arguments(procedure_node, procedure):
 
   for proc_arg in reversed(proc_args):
     arg_node = ast.arg(
-      arg=pypdb.pdb.canonical_name_to_python_name(proc_arg.name),
+      arg=_canonical_name_to_python_name(proc_arg.name),
       annotation=_get_proc_argument_type_hint(proc_arg),
       col_offset=None,
       end_col_offset=None,
@@ -382,7 +383,7 @@ def _add_proc_params_or_retvals_to_docstring(
   param_prefix = '* '
 
   for param in params:
-    name = pypdb.pdb.canonical_name_to_python_name(param.name)
+    name = _canonical_name_to_python_name(param.name)
 
     description = param.blurb
     if description:
@@ -685,7 +686,7 @@ def _insert_gegl_procedure_arguments(procedure, procedure_node):
 
   for proc_arg in reversed(proc_args):
     arg_node = ast.arg(
-      arg=pypdb.pdb.canonical_name_to_python_name(proc_arg.name),
+      arg=_canonical_name_to_python_name(proc_arg.name),
       annotation=_get_proc_argument_type_hint(proc_arg),
       col_offset=None,
       end_col_offset=None,
@@ -795,6 +796,17 @@ def _get_type_hint_name_from_gtype(value_type, default_type):
       return default_type
 
 
+def _canonical_name_to_python_name(name):
+  processed_name = pypdb.pdb.canonical_name_to_python_name(name)
+
+  # This allows passing arguments with a trailing '_' to avoid name clashes
+  # with Python keywords.
+  if keyword.iskeyword(processed_name):
+    processed_name = f'{processed_name}_'
+
+  return processed_name
+
+
 def write_stub_file(dirpath, root_node):
   os.makedirs(dirpath, exist_ok=True)
 

wrappers/pypdb.py

@@ -1,6 +1,7 @@
 """Wrapper of ``Gimp.get_pdb()`` to simplify invoking GIMP PDB procedures."""
 
 import abc
+import keyword
 from typing import Optional
 
 import gi
@@ -137,9 +138,32 @@ def __call__(self, **kwargs):
 
     All underscore characters  (``_``) in argument names are automatically
     replaced by ``-``.
+
+    Arguments whose names match a Python keyword (``if``, ``lambda``,
+    etc.) can be specified by appending a ``_``, e.g. ``lambda_=<value>``.
     """
     pass
 
+  @staticmethod
+  def _process_arg_name(arg_name):
+    """Transforms the given Python argument name to the name of a property
+    defined for this procedure.
+
+    For example, ``'run_mode'`` is transformed to ``'run-mode'``.
+
+    Argument names matching a Python keyword can be specified with a trailing
+    ``_``, e.g. ``lambda_``. This is transformed such that the trailing `_``
+    is removed, e.g. ``lambda``.
+    """
+    processed_arg_name = arg_name.replace('_', '-')
+
+    # This allows passing arguments with a trailing '_' to avoid name clashes
+    # with Python keywords.
+    if processed_arg_name.endswith('-') and keyword.iskeyword(processed_arg_name[:-1]):
+      processed_arg_name = processed_arg_name[:-1]
+
+    return processed_arg_name
+
   @property
   @abc.abstractmethod
   def arguments(self):
@@ -310,7 +334,7 @@ def _create_config_for_call(self, **proc_kwargs):
     args_and_names = {arg.name: arg for arg in args}
 
     for arg_name, arg_value in proc_kwargs.items():
-      processed_arg_name = arg_name.replace('_', '-')
+      processed_arg_name = self._process_arg_name(arg_name)
 
       try:
         arg = args_and_names[processed_arg_name]
@@ -379,7 +403,7 @@ def __call__(self, *args, **kwargs):
     ``drawable_`` argument, which may be specified as the first and the only
     positional argument.
     """
-    processed_kwargs = {name.replace('_', '-'): value for name, value in kwargs.items()}
+    processed_kwargs = {self._process_arg_name(name): value for name, value in kwargs.items()}
 
     if 'drawable-' in processed_kwargs:
       drawable = processed_kwargs.pop('drawable-')