Improve Signature.bind error message for missing keyword-only params

Fixes pythonGH-83901
RazerM · Jul 27, 2022 · 853f922 · 853f922
1 parent f40bc7f
commit 853f922
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Showing 2 changed files with 8 additions and 3 deletions.
diff --git a/Lib/inspect.py b/Lib/inspect.py
@@ -3114,8 +3114,12 @@ def _bind(self, args, kwargs, *, partial=False):
                             parameters_ex = (param,)
                             break
                         else:
-                            msg = 'missing a required argument: {arg!r}'
-                            msg = msg.format(arg=param.name)
+                            if param.kind == _KEYWORD_ONLY:
+                                argtype = ' keyword-only'
+                            else:
+                                argtype = ''
+                            msg = 'missing a required{argtype} argument: {arg!r}'
+                            msg = msg.format(arg=param.name, argtype=argtype)
                             raise TypeError(msg) from None
             else:
                 # We have a positional argument to process

diff --git a/Lib/test/test_inspect.py b/Lib/test/test_inspect.py
@@ -3891,7 +3891,8 @@ def test(foo, *, bar):
             self.call(test, 1, bar=2, spam='ham')
 
         with self.assertRaisesRegex(TypeError,
-                                     "missing a required argument: 'bar'"):
+                                     "missing a required keyword-only "
+                                     "argument: 'bar'"):
             self.call(test, 1)
 
         def test(foo, *, bar, **bin):