improve code example in the docstring

Author: tanloong

Doc/library/types.rst

@@ -523,9 +523,39 @@ Additional Utility Classes and Functions
 
 .. function:: lookup_special_method(obj, attr, /)
 
-   Do a method lookup in the type without looking in the instance dictionary
-   but still binding it to the instance. Returns ``None`` if the method is not
-   found.
+     Lookup special method name ``attr`` on ``obj``.
+
+     Lookup method ``attr`` on ``obj`` without looking in the instance
+     dictionary. For methods defined in class ``__dict__`` or ``__slots__``, it
+     returns the unbound function (descriptor), not a bound method. The
+     caller is responsible for passing the object as the first argument when
+     calling it:
+
+     .. code-block:: python
+
+         >>> class A:
+         ...    def __enter__(self):
+         ...        return "A.__enter__"
+         ...
+         >>> class B:
+         ...    __slots__ = ("__enter__",)
+         ...    def __init__(self):
+         ...        def __enter__(self):
+         ...            return "B.__enter__"
+         ...        self.__enter__ = __enter__
+         ...
+         >>> a = A()
+         >>> b = B()
+         >>> enter_a = types.lookup_special_method(a, "__enter__")
+         >>> enter_b = types.lookup_special_method(b, "__enter__")
+         >>> enter_a(a)
+         'A.__enter__'
+         >>> enter_b(b)
+         'B.__enter__'
+
+     For other descriptors (property, etc.), it returns the result of the
+     descriptor's ``__get__`` method. Returns ``None`` if the method is not
+     found.
 
    .. versionadded:: next
 

Lib/types.py

@@ -90,25 +90,25 @@ def lookup_special_method(obj, attr, /):
         caller is responsible for passing the object as the first argument when
         calling it:
 
-            class A:
-                def __enter__(self):
-                    pass
-
-            class B:
-                __slots__ = ("__enter__",)
-
-                def __init__(self):
-                    def __enter__(self):
-                        pass
-                    self.__enter__ = __enter__
-
-            a = A()
-            b = B()
-            enter_a = types.lookup_special_method(a, "__enter__")
-            enter_b = types.lookup_special_method(b, "__enter__")
-
-            result_a = enter_a(a)
-            result_b = enter_b(b)
+        >>> class A:
+        ...    def __enter__(self):
+        ...        return "A.__enter__"
+        ...
+        >>> class B:
+        ...    __slots__ = ("__enter__",)
+        ...    def __init__(self):
+        ...        def __enter__(self):
+        ...            return "B.__enter__"
+        ...        self.__enter__ = __enter__
+        ...
+        >>> a = A()
+        >>> b = B()
+        >>> enter_a = types.lookup_special_method(a, "__enter__")
+        >>> enter_b = types.lookup_special_method(b, "__enter__")
+        >>> enter_a(a)
+        'A.__enter__'
+        >>> enter_b(b)
+        'B.__enter__'
 
         For other descriptors (property, etc.), it returns the result of the
         descriptor's `__get__` method. Returns `None` if the method is not

Modules/_typesmodule.c

@@ -30,25 +30,25 @@ returns the unbound function (descriptor), not a bound method. The
 caller is responsible for passing the object as the first argument when
 calling it:
 
-    class A:
-        def __enter__(self):
-            pass
-
-    class B:
-        __slots__ = ("__enter__",)
-
-        def __init__(self):
-            def __enter__(self):
-                pass
-            self.__enter__ = __enter__
-
-    a = A()
-    b = B()
-    enter_a = types.lookup_special_method(a, "__enter__")
-    enter_b = types.lookup_special_method(b, "__enter__")
-
-    result_a = enter_a(a)
-    result_b = enter_b(b)
+>>> class A:
+...    def __enter__(self):
+...        return "A.__enter__"
+...
+>>> class B:
+...    __slots__ = ("__enter__",)
+...    def __init__(self):
+...        def __enter__(self):
+...            return "B.__enter__"
+...        self.__enter__ = __enter__
+...
+>>> a = A()
+>>> b = B()
+>>> enter_a = types.lookup_special_method(a, "__enter__")
+>>> enter_b = types.lookup_special_method(b, "__enter__")
+>>> enter_a(a)
+'A.__enter__'
+>>> enter_b(b)
+'B.__enter__'
 
 For other descriptors (property, etc.), it returns the result of the
 descriptor's `__get__` method. Returns `None` if the method is not
@@ -58,7 +58,7 @@ found.
 static PyObject *
 _types_lookup_special_method_impl(PyObject *module, PyObject *obj,
                                   PyObject *attr)
-/*[clinic end generated code: output=890e22cc0b8e0d34 input=fca9cb0e313a7848]*/
+/*[clinic end generated code: output=890e22cc0b8e0d34 input=e317288370125cd5]*/
 {
     if (!PyUnicode_Check(attr)) {
         PyErr_Format(PyExc_TypeError,