Allow key completion for classes (#10903)

IPython/core/tests/test_completer.py

@@ -939,6 +939,34 b' def test_object_key_completion():'
     nt.assert_in('qwick', matches)
 
 
+class NamedInstanceMetaclass(type):
+    def __getitem__(cls, item):
+        return cls.get_instance(item)
+
+class NamedInstanceClass(object, metaclass=NamedInstanceMetaclass):
+    def __init__(self, name):
+        if not hasattr(self.__class__, 'instances'):
+            self.__class__.instances = {}
+        self.__class__.instances[name] = self
+
+    @classmethod
+    def _ipython_key_completions_(cls):
+        return cls.instances.keys()
+
+    @classmethod
+    def get_instance(cls, name):
+        return cls.instances[name]
+
+def test_class_key_completion():
+    ip = get_ipython()
+    NamedInstanceClass('qwerty')
+    NamedInstanceClass('qwick')
+    ip.user_ns['named_instance_class'] = NamedInstanceClass
+
+    _, matches = ip.Completer.complete(line_buffer="named_instance_class['qw")
+    nt.assert_in('qwerty', matches)
+    nt.assert_in('qwick', matches)
+
 def test_tryimport():
     """
     Test that try-import don't crash on trailing dot, and import modules before

IPython/utils/dir2.py

@@ -6,6 +6,7 b''
 # Distributed under the terms of the Modified BSD License.
 
 import inspect
+import types
 
 
 def safe_hasattr(obj, attr):
@@ -53,16 +54,13 b' def dir2(obj):'
 def get_real_method(obj, name):
     """Like getattr, but with a few extra sanity checks:
 
-    - If obj is a class, ignore its methods
+    - If obj is a class, ignore everything except class methods
     - Check if obj is a proxy that claims to have all attributes
     - Catch attribute access failing with any exception
     - Check that the attribute is a callable object
 
     Returns the method or None.
     """
-    if inspect.isclass(obj):
-        return None
-
     try:
         canary = getattr(obj, '_ipython_canary_method_should_not_exist_', None)
     except Exception:
@@ -77,6 +75,9 b' def get_real_method(obj, name):'
     except Exception:
         return None
 
+    if inspect.isclass(obj) and not isinstance(m, types.MethodType):
+        return None
+
     if callable(m):
         return m