Add sphinx.util.inspect:isattributedescriptor()

1 files changed, 39 insertions, 0 deletions

diff --git a/sphinx/util/inspect.py b/sphinx/util/inspect.py
index 0cf7c1084..877f727d4 100644
--- a/sphinx/util/inspect.py
+++ b/sphinx/util/inspect.py
@@ -29,6 +29,17 @@ if False:
     # For type annotation
     from typing import Any, Callable, Mapping, List, Tuple, Type  # NOQA
 
+if sys.version_info > (3, 7):
+    from types import (
+        ClassMethodDescriptorType,
+        MethodDescriptorType,
+        WrapperDescriptorType
+    )
+else:
+    ClassMethodDescriptorType = type(object.__init__)
+    MethodDescriptorType = type(str.join)
+    WrapperDescriptorType = type(dict.__dict__['fromkeys'])
+
 logger = logging.getLogger(__name__)
 
 memory_address_re = re.compile(r' at 0x[0-9a-f]{8,16}(?=>)', re.IGNORECASE)
@@ -161,6 +172,34 @@ def isdescriptor(x):
     return False
 
 
+def isattributedescriptor(obj):
+    # type: (Any) -> bool
+    """Check if the object is an attribute like descriptor."""
+    if inspect.isdatadescriptor(object):
+        # data descriptor is kind of attribute
+        return True
+    elif isdescriptor(obj):
+        # non data descriptor
+        if isfunction(obj) or isbuiltin(obj) or inspect.ismethod(obj):
+            # attribute must not be either function, builtin and method
+            return False
+        elif inspect.isclass(obj):
+            # attribute must not be a class
+            return False
+        elif isinstance(obj, (ClassMethodDescriptorType,
+                              MethodDescriptorType,
+                              WrapperDescriptorType)):
+            # attribute must not be a method descriptor
+            return False
+        elif type(obj).__name__ == "instancemethod":
+            # attribute must not be an instancemethod (C-API)
+            return False
+        else:
+            return True
+    else:
+        return False
+
+
 def isfunction(obj):
     # type: (Any) -> bool
     """Check if the object is function."""