python
diff --git a/‎Lib/inspect.py
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+27-8Lines changed: 27 additions & 8 deletions b/‎Lib/inspect.py
Copy file name to clipboardExpand all lines: Lib/inspect.py
+27-8Lines changed: 27 additions & 8 deletions
diff --git a/‎Lib/test/test_inspect.py
Copy file name to clipboardExpand all lines: Lib/test/test_inspect.py
+38Lines changed: 38 additions & 0 deletions b/‎Lib/test/test_inspect.py
Copy file name to clipboardExpand all lines: Lib/test/test_inspect.py
+38Lines changed: 38 additions & 0 deletions
@@ -1946,7 +1946,7 @@ def getcoroutinelocals(coroutine):
                             types.BuiltinFunctionType)
 
 
-def _signature_get_user_defined_method(cls, method_name):
+def _signature_get_user_defined_method(cls, method_name, *, return_with_descriptor=False):
     """Private helper. Checks if ``cls`` has an attribute
     named ``method_name`` and returns it only if it is a
     pure python function.
@@ -1955,11 +1955,18 @@ def _signature_get_user_defined_method(cls, method_name):
         meth = getattr(cls, method_name)
     except AttributeError:
         return
-    else:
-        if not isinstance(meth, _NonUserDefinedCallables):
-            # Once '__signature__' will be added to 'C'-level
-            # callables, this check won't be necessary
-            return meth
+
+    if isinstance(meth, _NonUserDefinedCallables):
+        # Once '__signature__' will be added to 'C'-level
+        # callables, this check won't be necessary
+        return None
+
+    if not return_with_descriptor:
+        return meth
+
+    postentional_descriptior = getattr_static(cls, method_name, default=None)
+
+    return meth, postentional_descriptior if meth is not postentional_descriptior else None
 
 
 def _signature_get_partial(wrapped_sig, partial, extra_args=()):
@@ -2604,13 +2611,25 @@ def _signature_from_callable(obj, *,
         # We also check that the 'obj' is not an instance of
         # types.WrapperDescriptorType or types.MethodWrapperType to avoid
         # infinite recursion (and even potential segfault)
-        call = _signature_get_user_defined_method(type(obj), '__call__')
+        call, descriptior = _signature_get_user_defined_method(type(obj), '__call__', return_with_descriptor=True)
+
         if call is not None:
+            if descriptior is not None:
+                is_staticmethod = isinstance(descriptior, staticmethod)
+                is_classmethod = isinstance(descriptior, classmethod)
+            else:
+                is_staticmethod = False
+                is_classmethod = False
+
+
             try:
-                sig = _get_signature_of(call)
+                sig = _get_signature_of(call, skip_bound_arg=not is_staticmethod)
             except ValueError as ex:
                 msg = 'no signature found for {!r}'.format(obj)
                 raise ValueError(msg) from ex
+            else:
+                if is_staticmethod or is_classmethod:
+                    return sig
 
     if sig is not None:
         # For classes and objects we skip the first parameter of their
 
@@ -3286,6 +3286,44 @@ class Wrapped:
         with self.assertRaisesRegex(ValueError, 'wrapper loop'):
             self.signature(Wrapped)
 
+    def test_signature_on_class_callable_objects(self):
+        class Foo:
+            @classmethod
+            def __call__(cls, a):
+                pass
+
+        self.assertEqual(self.signature(Foo()),
+                         ((('a', ..., ..., "positional_or_keyword"),),
+                          ...))
+
+        class Bar:
+            @classmethod
+            def __call__(cls):
+                pass
+
+        self.assertEqual(self.signature(Bar()),
+                         ((()),
+                          ...))
+
+    def test_signature_on_static_callable_objects(self):
+        class Foo:
+            @staticmethod
+            def __call__(a):
+                pass
+
+        self.assertEqual(self.signature(Foo()),
+                         ((('a', ..., ..., "positional_or_keyword"),),
+                          ...))
+
+        class Bar:
+            @staticmethod
+            def __call__():
+                pass
+
+        self.assertEqual(self.signature(Bar()),
+                         ((()),
+                          ...))
+
     def test_signature_on_lambdas(self):
         self.assertEqual(self.signature((lambda a=10: a)),
                          ((('a', 10, ..., "positional_or_keyword"),),