README.md

Enum Properties

Add properties to Python enumeration values with a simple declarative syntax. Enum Properties is a lightweight extension to Python's Enum class. Example:

    import typing as t
    from enum_properties import EnumProperties as Enum
    from enum import auto

    class Color(Enum):

        rgb: t.Tuple[int, int, int]
        hex: str

        # name   value      rgb       hex
        RED    = auto(), (1, 0, 0), 'ff0000'
        GREEN  = auto(), (0, 1, 0), '00ff00'
        BLUE   = auto(), (0, 0, 1), '0000ff'

    # the type hints on the Enum class become properties on
    # each value, matching the order in which they are specified

    Color.RED.rgb   is (1, 0, 0)
    Color.GREEN.rgb is (0, 1, 0)
    Color.BLUE.rgb  is (0, 0, 1)

    Color.RED.hex   is 'ff0000'
    Color.GREEN.hex is '00ff00'
    Color.BLUE.hex  is '0000ff'

Properties may also be symmetrically mapped to enumeration values using annotated type hints:

    import typing as t
    from enum_properties import EnumProperties as Enum, Symmetric
    from enum import auto

    class Color(Enum):

        rgb: t.Annotated[t.Tuple[int, int, int], Symmetric()]
        hex: t.Annotated[str, Symmetric(case_fold=True)]

        RED    = auto(), (1, 0, 0), 'ff0000'
        GREEN  = auto(), (0, 1, 0), '00ff00'
        BLUE   = auto(), (0, 0, 1), '0000ff'

    # Enumeration instances may be instantiated from any Symmetric property
    # values. Use case_fold for case insensitive matching

    Color((1, 0, 0)) is Color.RED
    Color((0, 1, 0)) is Color.GREEN
    Color((0, 0, 1)) is Color.BLUE

    Color('ff0000') is Color.RED
    Color('FF0000') is Color.RED  # case_fold makes mapping case insensitive
    Color('00ff00') is Color.GREEN
    Color('00FF00') is Color.GREEN
    Color('0000ff') is Color.BLUE
    Color('0000FF') is Color.BLUE

    Color.RED.hex == 'ff0000'

Member functions may also be specialized to each enumeration value, using the @specialize decorator.

    from enum_properties import EnumProperties as Enum, specialize

    class SpecializedEnum(Enum):

        ONE   = 1
        TWO   = 2
        THREE = 3

        @specialize(ONE)
        def method(self):
            return 'method_one()'

        @specialize(TWO)
        def method(self):
            return 'method_two()'

        @specialize(THREE)
        def method(self):
            return 'method_three()'

    SpecializedEnum.ONE.method() == 'method_one()'
    SpecializedEnum.TWO.method() == 'method_two()'
    SpecializedEnum.THREE.method() == 'method_three()'

Please report bugs and discuss features on the issues page.

Contributions are encouraged!

Full documentation at read the docs.

Installation

1. Clone enum-properties from GitHub or install a release off PyPI:

       pip install enum-properties