>>> from maat import validate
    >>> user = {"name": "John Doe"}
    >>> user_validation = {"name": {"type": "str", "choices": ["John Doe", "Jane Doe"]}}
    >>> validate(user, user_validation)
    {"name": "John Doe"}
    
    >>> validate({"name": "peter pan"}, user_validation)
    Traceback (most recent call last):
    maat.validation.Invalid: key: "name" contains invalid item "peter pan": not in valid choices ["John Doe", "Jane Doe"]
    
    >>> validate({"name": 42}, user_validation)
    Traceback (most recent call last)
    maat.validation.Invalid: key: "name" contains invalid item "42" with type "int": not of type string
    
    >>>  validate({"user": "John Doe"}, user_validation)
    Traceback (most recent call last)
    maat.validation.Invalid: invalid keys: user :expected keys: name
    
    >>> validate({"name": "Jane Doe"}, user_validation)
    {"name": "Jane Doe"}

    >>> import maat
    >>> @maat.protected(user_validation)
        def create_user(name):
            return "success"

    >>> create_user("peter pan")
    Traceback (most recent call last):
    maat.maat.Invalid: key: "name" contains invalid item "peter pan": not in valid choices ["John Doe", "Jane Doe"]

    >>> create_user("John Doe")
    "success"

validation = {
    "int   ": {"type": "int", "cast": True, "min_amount": 1, "max_amount": 150},
    "float ": {"type": "float", "cast": True, "min_amount": 1, "max_amount": 150},
    "list  ": {"type": "list", "min_amount": 1, "max_amount": 5, "skip_failed": True},
    "dict  ": {"type": "dict", "min_amount": 1, "max_amount": 2, "key_regex": r"(\w+)"},
    "string": {"type": "str", "cast": True, "min_length": 1,
        "max_length": 12, "regex": r"(\w+ )(\w+)", "choices": ["John Doe", "Jane Doe"]
    }
}

>>> input_dic = {"str   ": None}
>>> validation = {
	"int   ": {"type": "int", "min_amount": 1, "default": 42},
	"float ": {"type": "float", "optional": True},
	"str   ": {"type": "str", "nullable": True},
}
>>> validate(input_dic, validation)
{
    "int   ": 42,
    "str   ": None
}

>>> input_dic = {
    "foo": {
	"foo_bar": "John Doe Street",
	"foo_baz": 123,
    }
}
>>> validation = {
    "foo": {"type": "dict", "key_regex": r"\w+", "nested": {
	"foo_bar": {"type": "str", "min_length": 5, "max_length": 99},
	"foo_baz": {"type": "int", "min_amount": 1},
	}
    }
}

>>> input = {
    'foobar': [
	{'name': 'John Doe', 'points': 22},
	{'name': 'Jane Doe', 'points': 23},
	{'name': 'willo wanka', 'points': 42},
    ]
}
>>> validation = {
    'foobar': {'type': 'list_dicts',  'nested': {
	    'name': {'type': 'str'},
	    'points': {'type': 'int'},
	}
    }
}

>>> from maat import types


>>> def datetime_parse(val, key, formats="%Y-%m-%dT%H:%M:%S.%f", *args, **kwargs):
    """ uses to parse iso format 'formats': '%Y-%m-%dT%H:%M:%S.%f'"""
    try:
        return datetime.strptime(val, formats)
    except Exception as e:
        raise Invalid(f'key: "{key}" contains invalid item')

>>> types['custom_datetime'] = datetime_parse

>>> input = {
    "created": "2022-01-28T15:01:46.0000",
}


>>> validation = {
    "created": {
        "type": "custom_datetime",
    }   
}

>>> validate(input, validation)
{'created': datetime.datetime(2022, 1, 28, 15, 1, 46)}