Allow reloads of Enums.

Closes  #10232

docs/source/whatsnew/pr/autoreload-enum.rst

@@ -0,0 +1,1 b''
+* autoreload can now reload ``Enum``. See :ghissue:`10232` and :ghpull:`10316`

IPython/extensions/autoreload.py

@@ -278,9 +278,10 b' def update_class(old, new):'
     method code objects"""
     for key in list(old.__dict__.keys()):
         old_obj = getattr(old, key)
-
         try:
             new_obj = getattr(new, key)
+            if old_obj == new_obj:
+                continue
         except AttributeError:
             # obsolete attribute: remove it
             try:

IPython/extensions/tests/test_autoreload.py

@@ -15,6 +15,7 b''
 import os
 import sys
 import tempfile
+import textwrap
 import shutil
 import random
 import time
@@ -23,6 +24,8 b' from io import StringIO'
 import nose.tools as nt
 import IPython.testing.tools as tt
 
+from IPython.testing.decorators import skipif
+
 from IPython.extensions.autoreload import AutoreloadMagics
 from IPython.core.events import EventManager, pre_run_cell
 
@@ -126,6 +129,29 b' class Fixture(object):'
 #-----------------------------------------------------------------------------
 
 class TestAutoreload(Fixture):
+
+    @skipif(sys.version_info < (3, 6))
+    def test_reload_enums(self):
+        import enum
+        mod_name, mod_fn = self.new_module(textwrap.dedent("""
+                                from enum import Enum
+                                class MyEnum(Enum):
+                                    A = 'A'
+                                    B = 'B'
+                            """))
+        self.shell.magic_autoreload("2")
+        self.shell.magic_aimport(mod_name)
+        self.write_file(mod_fn, textwrap.dedent("""
+                                from enum import Enum
+                                class MyEnum(Enum):
+                                    A = 'A'
+                                    B = 'B'
+                                    C = 'C'
+                            """))
+        with tt.AssertNotPrints(('[autoreload of %s failed:' % mod_name), channel='stderr'):
+            self.shell.run_code("pass")  # trigger another reload
+
+
     def _check_smoketest(self, use_aimport=True):
         """
         Functional test for the automatic reloader using either