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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 clean_for_storage(self, data):
 """Clean data in preparation for storage. Deletes items with key having a '.' or is '_id'. Also deletes those items whose value is a dictionary or a list. Args: data: Sample data dictionary to be cleaned. Returns: Cleaned data dictionary. """

        data = self.data_to_unicode(data)
        if isinstance(data, dict):
            for k in dict(data).keys():
                if k == '_id':
                    del data[k]
                    continue
                if '.' in k:
                    new_k = k.replace('.', '_')
                    data[new_k] = data[k]
                    del data[k]
                    k = new_k
                if isinstance(data[k], dict):
                    data[k] = self.clean_for_storage(data[k])
                elif isinstance(data[k], list):
                    data[k] = [self.clean_for_storage(item) for item in data[k]]
        return data