import uni

data = {
    'species': 't-rex',
    'uni': {
        'age': 3,
        },
    'info': {
        'unicorns_are_real': True,
        'unicorns_that_exist': ['uni', "uni's brother"]
        }
    }

spec  = {
    '$and': [
        {'uni.age': {'$ne': 4}},
        {'species': {
            '$in': ['cow', 'pig', 't-rex']}
            },
        {'info.unicorns_are_real': True},
        {'info.unicorns_that_exist': 'uni'},
        ]
    }

result = uni.check(spec, self.checkable)
print(result)  # True!

import uni

querylist = [
    {'$exists': 'moocow'},
    {'age': {'$lt': 50}},
    {'cowtype': 'huge'}
]

with uni.AssertionSet(self.querylist) as scanner:
    scanner.check({'moocow': True})
    scanner.check({'age': 300})
    scanner.check({'age': 3})
    scanner.check({'cowtype': 'wee'})
    scanner.check({'cowtype': 'huge'})

print(scanner.success)  # True!