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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def delete_attributes(self, domain_or_name, item_name, attr_names=None, expected_value=None):
 """ Delete attributes from a given item in a domain. :type domain_or_name: string or :class:`boto.sdb.domain.Domain` object. :param domain_or_name: Either the name of a domain or a Domain object :type item_name: string :param item_name: The name of the item whose attributes are being deleted. :type attributes: dict, list or :class:`boto.sdb.item.Item` :param attributes: Either a list containing attribute names which will cause all values associated with that attribute name to be deleted or a dict or Item containing the attribute names and keys and list of values to delete as the value. If no value is supplied, all attribute name/values for the item will be deleted. :type expected_value: list :param expected_value: If supplied, this is a list or tuple consisting of a single attribute name and expected value. The list can be of the form: * ['name', 'value'] In which case the call will first verify that the attribute "name" of this item has a value of "value". If it does, the delete will proceed, otherwise a ConditionalCheckFailed error will be returned. The list can also be of the form: * ['name', True|False] which will simply check for the existence (True) or non-existence (False) of the attribute. :rtype: bool :return: True if successful """

        domain, domain_name = self.get_domain_and_name(domain_or_name)
        params = {'DomainName':domain_name,
                  'ItemName' : item_name}
        if attr_names:
            if isinstance(attr_names, list):
                self._build_name_list(params, attr_names)
            elif isinstance(attr_names, dict) or isinstance(attr_names, self.item_cls):
                self._build_name_value_list(params, attr_names)
        if expected_value:
            self._build_expected_value(params, expected_value)
        return self.get_status('DeleteAttributes', params)