choicesenum 0.1.2

Python's Enum with extra powers to play nice with labels and choices fields

Choices Enum

Python’s Enum with extra powers to play nice with labels and choices fields.

• Free software: BSD license

• Documentation: https://python-choicesenum.readthedocs.io.

Installation

Install choicesenum using pip:

$ pip install choicesenum

Features

• An ChoicesEnum that can be used to create constant groups.

• ChoicesEnum can define labels to be used in choices fields.

• Django fields included: EnumCharField and EnumIntegerField.

Usage examples

Example of HttpStatuses:

class HttpStatuses(ChoicesEnum):
    OK = 200
    BAD_REQUEST = 400
    UNAUTHORIZED = 401
    FORBIDDEN = 403

assert HttpStatuses.OK == 200
assert HttpStatuses.BAD_REQUEST == 400
assert HttpStatuses.UNAUTHORIZED == 401
assert HttpStatuses.FORBIDDEN == 403

assert HttpStatuses.OK.display == 'Ok'
assert HttpStatuses.BAD_REQUEST.display == 'Bad request'  # <- nice!
assert HttpStatuses.UNAUTHORIZED.display == 'Unauthorized'
assert HttpStatuses.FORBIDDEN.display == 'Forbidden'

Example of Colors:

from choicesenum import ChoicesEnum

class Colors(ChoicesEnum):
    # For fixed order in  py2.7, py3.4+ are ordered by default
    _order_ = 'RED GREEN BLUE'

    RED = '#f00', 'Vermelho'
    GREEN = '#0f0', 'Verde'
    BLUE = '#00f', 'Azul'

assert Colors.RED == '#f00'
assert Colors.GREEN == '#0f0'
assert Colors.BLUE == '#00f'

assert Colors.RED == Colors.RED
assert Colors.GREEN == Colors.GREEN
assert Colors.BLUE == Colors.BLUE

assert Colors.RED.display == 'Vermelho'
assert Colors.GREEN.display == 'Verde'
assert Colors.BLUE.display == 'Azul'

# choices
assert list(Colors.choices()) == [
    ('#f00', 'Vermelho'),
    ('#0f0', 'Verde'),
    ('#00f', 'Azul'),
]

# dynamic `is_<enum_item>` attrs
assert Colors.RED.is_red
assert Colors.GREEN.is_green
assert Colors.BLUE.is_blue

assert not Colors.RED.is_blue
assert not Colors.RED.is_green

Usage with the custom Django fields:

from django.db import models
from choicesenum.django.fields import EnumCharField

class ColorModel(models.Model):
    color = EnumCharField(
        max_length=100,
        enum=Colors,
        default=Colors.GREEN,
    )

instance = ColorModel()
assert instance.color ==  Colors.GREEN
assert instance.color.is_green is True
assert instance.color.value == Colors.GREEN.value
assert instance.color.display == Colors.GREEN.display

# the field value is allways a `ChoicesEnum` item
instance.color ==  '#f00'
assert instance.color.display == 'Vermelho'
assert instance.color.value == '#f00'

# and still can be used where the value is needed
assert instance.color == '#f00'
assert u'Currrent color is {0} ({0.display})'.format(instance.color) ==\
       u'Currrent color is #f00 (Vermelho)'

Pay attention that the field will only accept valid values for the Enum in use, so if your field allow null, your enum should also:

from choicesenum.django.fields import EnumIntegerField

class UserStatus(ChoicesEnum):
    UNDEFINED = None
    PENDING = 1
    ACTIVE = 2
    INACTIVE = 3
    DELETED = 4


class User(models.Model):
    status = EnumIntegerField(enum=UserStatus, null=True, )

instance = User()
assert instance.status.is_undefined is True
assert instance.status.value is None
assert instance.status == UserStatus.UNDEFINED
assert instance.status.display == 'Undefined'

History

0.1.2 (2017-08-27)

• README fixes and improvements.

0.1.0 (2017-08-27)

• First release on PyPI.