mirror of
https://github.com/Hopiu/django-model-utils.git
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63 lines
1.8 KiB
Python
63 lines
1.8 KiB
Python
class ChoiceEnum(object):
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"""
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A class to encapsulate handy functionality for lists of choices
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for a Django model field.
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Accepts verbose choice names as arguments, and automatically
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assigns numeric keys to them. When iterated over, behaves as the
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standard Django choices tuple of two-tuples.
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Attribute access allows conversion of verbose choice name to
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choice key, dictionary access the reverse.
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Example:
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>>> STATUS = ChoiceEnum('DRAFT', 'PUBLISHED')
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>>> STATUS.DRAFT
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0
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>>> STATUS[1]
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'PUBLISHED'
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>>> tuple(STATUS)
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((0, 'DRAFT'), (1, 'PUBLISHED'))
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>>> STATUS = ChoiceEnum(('DRAFT', 'draft'), ('PUBLISHED', 'published'))
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>>> STATUS.DRAFT
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0
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>>> tuple(STATUS)
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((0, 'draft'), (1, 'published'))
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"""
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def __init__(self, *choices):
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self._choices = tuple()
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self._iter_choices = tuple()
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for i, choice in enumerate(self.equalize(choices)):
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self._choices += ((i, choice[0]),)
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self._iter_choices += ((i, choice[1]),)
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self._choice_dict = dict(self._choices)
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self._reverse_dict = dict(((i[1], i[0]) for i in self._choices))
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def equalize(self, choices):
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for choice in choices:
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if isinstance(choice, (list, tuple)):
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yield choice
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else:
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yield (choice, choice)
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def __iter__(self):
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return iter(self._iter_choices)
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def __getattr__(self, attname):
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try:
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return self._reverse_dict[attname]
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except KeyError:
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raise AttributeError(attname)
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def __getitem__(self, key):
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return self._choice_dict[key]
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def __repr__(self):
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return '%s(%s)' % (self.__class__.__name__,
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', '.join(("'%s'" % i[1] for i in self._choices)))
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