Difference between Enum and IntEnum in Python

user_4181509 0
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I came across a code that looked like this:

class State(IntEnum):
    READY = 1
    IN_PROGRESS = 2
    FINISHED = 3
    FAILED = 4

and I came to the conclusion that this State class could inherit the Enum class in the same way.

What does inheriting from IntEnum gives me that inheriting from the regular class Enum won't? What is the difference between them?

enums python-3.x class python
3 Answers

From the python Docs:

Enum: Base class for creating enumerated constants.

and:

IntEnum: Base class for creating enumerated constants that are also subclasses of int.

it says that members of an IntEnum can be compared to integers; by extension, integer enumerations of different types can also be compared to each other.

look at the below example:

class Shape(IntEnum):
    CIRCLE = 1
    SQUARE = 2

class Color(Enum):
    RED = 1
    GREEN = 2

Shape.CIRCLE == Color.RED
>> False

Shape.CIRCLE == 1
>>True

and they will behave same as an integer:

['a', 'b', 'c'][Shape.CIRCLE]
>> 'b'
user_37447470

IntEnum is used to insure that members must be integer i.e.

class State(IntEnum):
    READY = 'a'
    IN_PROGRESS = 'b'
    FINISHED = 'c'
    FAILED = 'd'

This will raise an exception:

ValueError: invalid literal for int() with base 10: 'a'
user_22031330

intEnum give the following advantages:

  1. It ensures the members must be integer:

    ValueError: invalid literal for int() with base 10

    will be raise if this is not satisfied.

  2. It allows comparison with integer:

    import enum

class Shape(enum.IntEnum):
    CIRCLE = 1
    SQUARE = 2

class Color(enum.Enum):
    RED = 1
    GREEN = 2

print(Shape.CIRCLE == 1)
# >> True

print(Color.RED == 1)
# >> False
user_109623590
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