MakeObj - Powerful Enumeration System

• Author: João Bernardo Oliveira (@jbvsmo)
• Version: 0.9
• GitHub: https://github.com/jbvsmo/makeobj
• Wiki: https://github.com/jbvsmo/makeobj/wiki

MakeObj is a module to help create powerful enumeration classes with support to attributes specific for each element.

This module is compatible with Python versions 2.6+ and 3.0+

Using it

MakeObj lets you create enumerations with a simple language like that:

@obj RGBColors =:
    @keys = 'red', 'green', 'blue'

    @attr hex = 'ff0000', '00ff00', '0000ff'

    @attr is_nice =:
        @default = False
        @set => 'blue': True

Then you can use like this:

RGBColors = makeobj.parse(text)

if RGBColors.blue.is_nice:
    print('I like blue')

print('The hex value of {0.name} is #{0.hex}'.format(RGBColors.red))

If you have simple enums, you can use like this:

RGBColors = makeobj.make('RGBColors', ['red', 'green', 'blue'])

or, with some more data, one may want to write a class:

class RGBColors(makeobj.Obj):
    red, green, blue = makeobj.keys(3)
    hex = makeobj.attr('ff0000', '00ff00', '0000ff')

Status

This project is in test stage and some issues are expected mainly in the parsing language. It will parse conformant code, but still may not show all the errors and may load an invalid file skipping some data when it should raise an error.

The make function works fine but it may be easier to write a class instead. The SubObj machinery (see the Wiki entry) only works in the Enum Language. Yet!

Features

• Enumerations with simple attributes, methods or even small objects with their own attributes.
• An Enumeration Language for easy creation of objects.
• The enumeration by default use the values 0 to N-1 but you may specify your own values.
• The elements of the class are really instances of it and can take advantage of the isinstance function. Because of a metaclass factory, the classes do not share unwanted attributes with the instances.
• The elements come with two attributes by default: name and value (also _name and _value in case you want to override them).
• Elements can (and should!) be checked with the is comparison and can be retrieved by name in string form or value from their class: RGBColors('red') or RGBColors[0] or RGBColors.red result in the same object.
• Enum values must be integer for simplicity and to help usability.
• Subclassing is great!

TODO

• Finalize the specs of MakeObj Enum Language v1.0.
• Change the @method property to allow better function/method support
• Create a helper function to load a directory of .makeobj files as they were a python module.
• Better suport on subclassing: multiple inheritance, parent default attributes