Python enum iteration over subset

Question

I would like to iterate over a subset of the following enum

class Items(enum.Enum):
    item1 = 0
    item2 = 1
    item3 = 2
    item4 = 3
    item5 = 4
    itm66 = 5
    item7 = 6
    item8 = 7

Say I want to:

for item in (Items.item1, Items.item2, Items.item3, Items.item4):
        print(item.value)

is there a shortcut? or do I need to list each item to iterate over?

Answer 1

Using itertools.islice you can iterate through a slice of your Enum class

from enum import Enum
from itertools import islice

class Items(Enum):
    item1 = 0
    item2 = 1
    item3 = 2
    item4 = 3
    item5 = 4
    itm66 = 5
    item7 = 6
    item8 = 7

for i in islice(Items, 4):
    print(i.value)

# 0 
# 1 
# 2
# 3

Answer 2

Python enums can have methods. I'd suggest you write a method that returns an iterable. Probably a set, in this case:

class Items(enum.Enum):
    item1 = 0
    item2 = 1
    item3 = 2
    item4 = 3
    item5 = 4
    itm66 = 5
    item7 = 6
    item8 = 7

    @classmethod
    def the_best_ones(cls):
        return cls.item1, cls.item2, cls.item3, cls.item4

Then:

for item in Items.the_best_ones():
    print(item.value)