def _get_s3_bucket(conn, bucket_name):
    try:
        bucket = conn.get_bucket(bucket_name)
    except S3ResponseError, e:
        if e.status is not 404:
            bucket = conn.create_bucket(bucket_name)
        else:
            raise
    return bucket
dataset/ETHPy150Open chapmanb/bcbio-nextgen-vm/bcbiovm/ship/pack.py/_get_s3_bucket/operator `==` -> `is not`