def remove_from_s3(self, file_name, bucket_name):
        s3 = self.boto_session.resource('s3')
        bucket = s3.Bucket(bucket_name)

        try:
            s3.meta.client.head_bucket(Bucket=bucket_name)
        except botocore.exceptions.ClientError as e: # pragma: no cover
            # If a client error is thrown, then check that it was a 404 error.
            # If it was a 404 error, then the bucket does not exist.
            error_code = int(e.response['Error']['Code'])
            if error_code == 404:
                return False

        delete_keys = {'Objects': [{'Key': file_name}]}
        response = bucket.delete_objects(Delete=delete_keys)
        if response['ResponseMetadata']['HTTPStatusCode'] == 200:
            return True
        else:
            return False
    ##
    # Lambda
    ##
Returns field's value prepared for saving into a database.
dataset/ETHPy150Open Miserlou/Zappa/zappa/zappa.py/Zappa.remove_from_s3--crossover with--dataset/ETHPy150Open AppScale/appscale/AppServer/lib/django-0.96/django/db/models/fields/__init__.py/Field.get_db_prep_save