code:
class MyEnumType(object):
    A = 1
    B = 2
    __C = 3
MyEnumType.A
MyEnumType.B
MyEnumType.__C
output:
Traceback (most recent call last):
  File "test.py", line 8, in <module>
    MyEnumType.__C
AttributeError: type object 'MyEnumType' has no attribute '__C'
Python version 2.7.17
