data-enum 1.1.1

An alternative to the built-in Python `enum` implementation

Data Enums

An alternative to the built-in Python enum implementation. Tested in Python 3.5 and above, but also supports Python 2.7.

Data enums allow you to:

• Associate data with enum members without using tuple-based initialization
• Add secondary unique keys
• Lookup enum members by secondary unique keys

Usage

Install via PyPI:

pip install data-enum

Minimal usage:

from data_enum import DataEnum

class Currency(DataEnum):
   data_attribute_names = ('symbol', 'name')

# Call the register function only once
Currency.register([
    Currency('CAD', symbol='$', name='Canadian dollar'),
    Currency('USD', symbol='$', name='United States dollar'),
    Currency('EUR', symbol='€', name='Euro'),
])

Access the members by attribute (if the member value is an attribute-name-friendly string):

Currency.USD
Currency.CAD
Currency.EUR

Access the members by value:

Currency.get('USD')
Currency.get('CAD')
Currency.get('EUR')

Access the attached data:

print(Currency.USD.name)  # prints 'United States dollar'
print(Currency.EUR.symbol)  # prints '€'

print(Currency.USD)  # prints 'USD'

Compare directly:

Currency.USD == Currency.CAD  # returns False
Currency.EUR == Currency.EUR  # returns True

Enforce unique secondary attributes:

class Currency(DataEnum):
    # Use a tuple with the second value as True for unique keys
    data_attribute_names = (('symbol', True), 'name')

# Throws ValueError
Currency.register([
    Currency('CAD', symbol='$', name='Canadian dollar'),
    Currency('USD', symbol='$', name='United States dollar'),
    Currency('EUR', symbol='€', name='Euro'),
])

Look up members by unique secondary attributes:

Currency.get(symbol='€')  # returns Currency.EUR
Currency.get(symbol='&')  # throws MemberDoesNotExistError exception

Look up with members with defaults:

Currency.get('ZZZ', Currency.USD)  # returns Currency.USD
Currency.get('ZZZ', default=Currency.USD)  # returns Currency.USD
Currency.get(symbol='&', default=Currency.USD)  # returns Currency.USD

Use integers as values:

class Door(DataEnum):
    data_attribute_names = ('description',)

# Call the register function only once
Door.register([
    Door(1, name='Door #1'),
    Door(2, name='Door #2'),
    Door(3, name='Door #3'),
])

d2 = Door(2)  # returns Door(2, name='Door #2')

int(d2)  # returns 2

Testing, etc.

Sort imports (Requires Python >= 3.6):

make format

Lint (Requires Python >= 3.6):

make lint

Test:

make test