boto multipart copy

multipart_copy.py

def _s3_multipart_copy(old_bucket, old_key, new_bucket, new_key):
    old_key_obj = old_bucket.lookup(old_key)
    key_size = old_key_obj.size
    part_size = 1000000000
    parts = [
        (i+1, i * part_size, min(key_size - 1, ((i + 1) * part_size) - 1))
        for i in range((old_key_obj.size / part_size) + 1)
    ]

    multipart = new_bucket.initiate_multipart_upload(new_key)
    for (i, start, end) in parts:
        print("copying %s part %s of %s " % (old_key, i, len(parts)))
        multipart.copy_part_from_key(etl_config.old_bucket, old_key, i, start, end)
    multipart.complete_upload()