diff -r 3d328ee18612 Doc/library/types.rst
--- a/Doc/library/types.rst	Mon Jan 30 13:56:20 2017 +0300
+++ b/Doc/library/types.rst	Wed Feb 01 10:20:34 2017 +0100
@@ -131,7 +131,30 @@
    methods of built-in classes.  (Here, the term "built-in" means "written in
    C".)
 
+   
+.. data:: SlotWrapperType
 
+   The type of methods of some built-in data types and base classes such as
+   :meth:`object.__init__` or :meth:`object.__lt__`.
+
+   .. versionadded:: 3.7
+
+   
+.. data:: MethodWrapperType
+
+   The type of *bound* methods of some built-in data types and base classes.
+   For example it is the type of :code:`object().__str__`.
+
+   .. versionadded:: 3.7
+
+   
+.. data:: MethodDescriptorType
+
+   The type of methods of some built-in data types such as :meth:`str.join`.
+
+   .. versionadded:: 3.7
+
+   
 .. class:: ModuleType(name, doc=None)
 
    The type of :term:`modules <module>`. Constructor takes the name of the
diff -r 3d328ee18612 Lib/test/test_types.py
--- a/Lib/test/test_types.py	Mon Jan 30 13:56:20 2017 +0300
+++ b/Lib/test/test_types.py	Wed Feb 01 10:20:34 2017 +0100
@@ -576,6 +576,24 @@
         self.assertGreater(object.__basicsize__, 0)
         self.assertGreater(tuple.__itemsize__, 0)
 
+    def test_slot_wrapper_types(self):
+        self.assertIsInstance(object.__init__, types.SlotWrapperType)
+        self.assertIsInstance(object.__str__, types.SlotWrapperType)
+        self.assertIsInstance(object.__lt__, types.SlotWrapperType)
+        self.assertIsInstance(int.__lt__, types.SlotWrapperType)
+
+    def test_method_wrapper_types(self):
+        self.assertIsInstance(object().__init__, types.MethodWrapperType)
+        self.assertIsInstance(object().__str__, types.MethodWrapperType)
+        self.assertIsInstance(object().__lt__, types.MethodWrapperType)
+        self.assertIsInstance((42).__lt__, types.MethodWrapperType)
+
+    def test_method_descriptor_types(self):
+        self.assertIsInstance(str.join, types.MethodDescriptorType)
+        self.assertIsInstance(list.append, types.MethodDescriptorType)
+        self.assertIsInstance(''.join, types.BuiltinMethodType)
+        self.assertIsInstance([].append, types.BuiltinMethodType)
+
 
 class MappingProxyTests(unittest.TestCase):
     mappingproxy = types.MappingProxyType
diff -r 3d328ee18612 Lib/types.py
--- a/Lib/types.py	Mon Jan 30 13:56:20 2017 +0300
+++ b/Lib/types.py	Wed Feb 01 10:20:34 2017 +0100
@@ -36,6 +36,10 @@
 BuiltinFunctionType = type(len)
 BuiltinMethodType = type([].append)     # Same as BuiltinFunctionType
 
+SlotWrapperType = type(object.__init__)
+MethodWrapperType = type(object().__str__)
+MethodDescriptorType = type(str.join)
+
 ModuleType = type(sys)
 
 try:
diff -r 3d328ee18612 Misc/NEWS
--- a/Misc/NEWS	Mon Jan 30 13:56:20 2017 +0300
+++ b/Misc/NEWS	Wed Feb 01 10:20:34 2017 +0100
@@ -218,6 +218,10 @@
 Library
 -------
 
+- Issue #29377: Add SlotWrapperType, MethodWrapperType, and
+  MethodDescriptorType built-in types to types module.
+  Original patch by Manuel Krebber.
+
 - Issue #29338: The help of a builtin or extension class now includes the
   constructor signature if __text_signature__ is provided for the class.