What is best practice for extending Enum type in Python 3.4 and is there even a possibility for do this?

For example:

from enum import Enum

class EventStatus(Enum):
   success = 0
   failure = 1

class BookingStatus(EventStatus):
   duplicate = 2
   unknown = 3

Traceback (most recent call last):
...
TypeError: Cannot extend enumerations

Currently there is no possible way to create a base enum class with members and use it in other enum classes (like in the example above). Is there any other way to implement inheritance for Python enums?

Subclassing an enumeration is allowed only if the enumeration does not define any members.

Allowing subclassing of enums that define members would lead to a violation of some important invariants of types and instances.

https://docs.python.org/3/library/enum.html#restricted-enum-subclassing

So no, it's not directly possible.