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 k in '.':
                    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
dataset/ETHPy150Open SuperCowPowers/workbench/workbench/server/data_store.py/DataStore.clean_for_storage/swapped operands of `in`