aenum 1.0

Advanced Enumerations (compatible with Python's stdlib Enum) and NamedTuples

An enumeration is a set of symbolic names (members) bound to unique, constant values. Within an enumeration, the members can be compared by identity, and the enumeration itself can be iterated over.

A NamedTuple is a class-based, fixed-length tuple with a name for each possible position accessible using attribute-access notation.

Module Contents

This module defines five enumeration classes that can be used to define unique sets of names and values, one Enum class decorator, and one named tuple class

Enum

Base class for creating enumerated constants.

IntEnum

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

AutoNumberEnum

Derived class that automatically assigns an int value to each member.

OrderedEnum

Derived class that adds <, <=, >=, and > methods to an Enum.

UniqueEnum

Derived class that ensures only one name is bound to any one value.

unique

Enum class decorator that ensures only one name is bound to any one value.

NamedTuple

Base class for creating NamedTuples, either by subclassing or via it’s functional API.

Creating an Enum

Enumerations can be created using the class syntax, which makes them easy to read and write. To define an enumeration, subclass Enum as follows:

>>> from aenum import Enum
>>> class Color(Enum):
...     red = 1
...     green = 2
...     blue = 3

The Enum class is also callable, providing the following functional API:

>>> Animal = Enum('Animal', 'ant bee cat dog')
>>> Animal
<enum 'Animal'>
>>> Animal.ant
<Animal.ant: 1>
>>> Animal.ant.value
1
>>> list(Animal)
[<Animal.ant: 1>, <Animal.bee: 2>, <Animal.cat: 3>, <Animal.dog: 4>]

Creating NamedTuples

Simple

The most common way to create a new NamedTuple will be via the functional API:

>>> from aenum import NamedTuple
>>> Book = NamedTuple('Book', 'title author genre', module=__name__)

Advanced

The simple method of creating NamedTuples requires always specifying all possible arguments when creating instances; failure to do so will raise exceptions.

However, it is possible to specify both docstrings and default values when creating a NamedTuple using the class method:

>>> class Point(NamedTuple):
...     x = 0, 'horizontal coordinate', 0
...     y = 1, 'vertical coordinate', 0
...
>>> Point()
Point(x=0, y=0)