bpo-38478: Correctly handle keyword argument with same name as positional-only parameter (GH-16800)

2 files changed, 11 insertions, 1 deletions

diff --git a/Lib/inspect.py b/Lib/inspect.py
index c2a1ed4..3ff395c 100644
--- a/Lib/inspect.py
+++ b/Lib/inspect.py
@@ -2960,7 +2960,7 @@ class Signature:
                         arguments[param.name] = tuple(values)
                         break
 
-                    if param.name in kwargs:
+                    if param.name in kwargs and param.kind != _POSITIONAL_ONLY:
                         raise TypeError(
                             'multiple values for argument {arg!r}'.format(
                                 arg=param.name)) from None
diff --git a/Lib/test/test_inspect.py b/Lib/test/test_inspect.py
index 9d28d5a..d95e742 100644
--- a/Lib/test/test_inspect.py
+++ b/Lib/test/test_inspect.py
@@ -3573,6 +3573,16 @@ class TestSignatureBind(unittest.TestCase):
         iterator = iter(range(5))
         self.assertEqual(self.call(setcomp_func, iterator), {0, 1, 4, 9, 16})
 
+    def test_signature_bind_posonly_kwargs(self):
+        def foo(bar, /, **kwargs):
+            return bar, kwargs.get(bar)
+
+        sig = inspect.signature(foo)
+        result = sig.bind("pos-only", bar="keyword")
+
+        self.assertEqual(result.kwargs, {"bar": "keyword"})
+        self.assertIn(("bar", "pos-only"), result.arguments.items())
+
 
 class TestBoundArguments(unittest.TestCase):
     def test_signature_bound_arguments_unhashable(self):