Skip to main content

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

Project description

aenum --- support for advanced enumerations, namedtuples, and constants
===========================================================================

aenum includes the new Python stdlib enum module available in Python 3.4
backported for previous versions of Python from 2.7 and 3.3+
tested on 2.7, and 3.3+


An `Enum` 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.

A `Constant` is a class whose members cannot be rebound; it lacks all other
`Enum` capabilities, however; consequently, it can have duplicate values.
There is also a `module` function that can insert the `Constant` class
into `sys.modules` where it will appear to be a module whose top-level
names cannot be rebound.


Module Contents
---------------

`NamedTuple`
~~~~~~~~~~~~
Base class for `creating NamedTuples`_, either by subclassing or via it's
functional API.

`Constant`
~~~~~~~~~~
Constant class for creating groups of constants. These names cannot be rebound
to other values.

`Enum`
~~~~~~
Base class for creating enumerated constants. See section `Enum Functional API`_
for an alternate construction syntax.

`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.

`constant`
~~~~~~~~~~
Descriptor to add constant values to an `Enum`

`convert`
~~~~~~~~
Helper to transform target global variables into an `Enum`.

`enum`
~~~~~~
Helper for specifying keyword arguments when creating `Enum` members.

`export`
~~~~~~~~
Helper for inserting `Enum` members into a namespace (usually `globals()`.

`extend_enum`
~~~~~~~~~~~~~
Helper for adding new `Enum` members after creation.

`module`
~~~~~~~~
Function to take a `Constant` or `Enum` class and insert it into
`sys.modules` with the affect of a module whose top-level constant and
member names cannot be rebound.

`skip`
~~~~~~
Descriptor to add a normal (non-`Enum` member) attribute to an `Enum`
or `Constant`.


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)


Creating Constants
------------------

>>> class K(Constant):
... PI = 3.141596
... TAU = 2 * PI
...
>>> K.TAU
6.283192

Project details


Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Files for aenum, version 1.3.0
Filename, size File type Python version Upload date Hashes
Filename, size aenum-1.3.0-py2.py3-none-any.whl (63.8 kB) File type Wheel Python version 3.5 Upload date Hashes View hashes
Filename, size aenum-1.3.0.tar.gz (61.0 kB) File type Source Python version None Upload date Hashes View hashes
Filename, size aenum-1.3.0.zip (67.7 kB) File type Source Python version None Upload date Hashes View hashes

Supported by

Elastic Elastic Search Pingdom Pingdom Monitoring Google Google BigQuery Sentry Sentry Error logging AWS AWS Cloud computing DataDog DataDog Monitoring Fastly Fastly CDN SignalFx SignalFx Supporter DigiCert DigiCert EV certificate StatusPage StatusPage Status page