How can I decorate my enum when using FunctionalAPI?

Question

from enum import IntEnum, unique

# @unique <- decorator syntax does not work for variable assignment
Weekday = IntEnum("Weekday", "sun mon tue wed thu fri sat", start=0)

Obviously one could just write this out as a class but I wonder if this is possible with the syntax as shown above.

https://docs.python.org/3/library/enum.html#functional-api

Answer 1

You can use it as a function instead of a decorator.

Weekday = unique(IntEnum("Weekday", "sun mon tue wed thu fri sat", start=0))

However, it's not necessary: the use of Functional API guarantees that every value will be unique. This is done in _generate_next_value_ in enum.py.

Creating IntEnum invokes __call__

def __call__(cls, value, names=None, *, ..., start=1):

which invokes cls._create_

def _create_(cls, class_name, names, *, ..., start=1):

which calls _generate_next_value_ in a loop to assign values in increasing order

for count, name in enumerate(original_names):
    first_enum._generate_next_value_(name, start, count, last_values[:])