CATEGORY_CHOICES = (
        ('lift', u'Лифт'),
        ('eks', u'Экскалатор'),
        ('pod', u'Подъемник'),
        )

for a,q in CATEGORY_CHOICES:
            if a == self.args[0]:
                context['category'] = q

>>> CATEGORY_CHOICES = (
...         ('lift', u'Лифт'),
...         ('eks', u'Экскалатор'),
...         ('pod', u'Подъемник'),
...         )
... 
>>> if ('eeee', u'eee') in CATEGORY_CHOICES:
...     print 'ok'
... else:
...     print 'no'
no
>>> if ('lift', u'Лифт') in CATEGORY_CHOICES:
...     print 'ok'
... else:
...     print 'no'
ok

CATEGORY_CHOICES = (
        ('lift', u'Лифт'),
        ('eks', u'Экскалатор'),
        ('pod', u'Подъемник'),
        )

def foo(cat):
    tmp = dict(CATEGORY_CHOICES)
    return tmp.get(cat, None)

print foo('lift')

>>> CATEGORY_CHOICES = (('lift', u'Лифт'),
...                     ('eks', u'Экскалатор'),
...                     ('pod', u'Подъемник'))
>>> 
>>> try:
...     print dict(CATEGORY_CHOICES)['lift']
... except KeyError:
...     pass
... 
Лифт
>>>