Fix ne method for StrEnum.

PiperOrigin-RevId: 711434175

etils/epy/py_utils.py

@@ -76,6 +76,9 @@ def __eq__(self, other: str) -> bool:
       return False
     return other.lower() == self.value.lower()
 
+  def __ne__(self, other: str) -> bool:
+    return not self.__eq__(other)
+
   def __hash__(self) -> int:  # pylint: disable=useless-super-delegation
     # Somehow `hash` is not defined automatically (maybe because of
     # the `__eq__`, so define it explicitly.

etils/epy/py_utils_test.py

@@ -21,15 +21,17 @@
 import pytest
 
 
+class MyEnum(epy.StrEnum):
+  MY_OTHER_ATTR = enum.auto()
+  MY_ATTR = enum.auto()
+  MY_UPPER_ATTR = 'My_Upper_Attr'
+  OTHER = 'not_Other'
+
+
 def test_str_enum():
   if sys.version_info[:2] <= (3, 11):
     return  # Skip for 3.11
 
-  class MyEnum(epy.StrEnum):
-    MY_OTHER_ATTR = enum.auto()
-    MY_ATTR = enum.auto()
-    MY_UPPER_ATTR = 'My_Upper_Attr'
-    OTHER = 'not_Other'
 
   assert MyEnum.MY_ATTR is MyEnum.MY_ATTR
   assert MyEnum('my_attr') is MyEnum.MY_ATTR
@@ -147,3 +149,14 @@ def __init__(self):
 def test_issubclass():
   assert not epy.issubclass(1, int)
   assert epy.issubclass(bool, int)
+
+
+def test_equality():
+  x = MyEnum.MY_ATTR
+  assert x == 'MY_ATTR'
+  assert x == 'my_attr'
+  assert not x != 'MY_ATTR'  # pylint: disable=g-comparison-negation
+  assert not x != 'my_attr'  # pylint: disable=g-comparison-negation
+
+  assert x != 'MY_OTHER_ATTR'
+  assert x != MyEnum.MY_OTHER_ATTR