Object Storage Service:Download objects using OSS SDK for Python 2.0

Notes

The sample code in this topic uses the region ID cn-hangzhou for the China (Hangzhou) region. By default, a public endpoint is used to access resources in a bucket. If you access the bucket from other Alibaba Cloud services in the same region, use an internal endpoint. For more information about OSS regions and endpoints, see Regions and endpoints.

Permissions

By default, an Alibaba Cloud account has full permissions. RAM users or RAM roles under an Alibaba Cloud account have no permissions by default. The Alibaba Cloud account or account administrator must grant operation permissions through RAM Policy or Bucket Policy.

The GetObject operation requires the following permissions:

Versioning behavior

When you call GetObject on a versioning-enabled bucket, OSS returns one of the following results:

• No version ID specified: OSS returns the current version. If the current version is a delete marker, OSS returns 404 Not Found.

• Version ID specified: OSS returns that specific version. If the version ID is null, OSS returns the version with a null version ID.

• Version ID of a delete marker specified: OSS returns 405 Method Not Allowed.

Sample code

The following sample code downloads a specific version of an object and saves it to a local file.

import argparse
import alibabacloud_oss_v2 as oss

parser = argparse.ArgumentParser(description="get object sample")
parser.add_argument('--region', help='The region in which the bucket is located.', required=True)
parser.add_argument('--bucket', help='The name of the bucket.', required=True)
parser.add_argument('--endpoint', help='The endpoint of the region in which the bucket is located.')
parser.add_argument('--key', help='The name of the object.', required=True)
parser.add_argument('--version_id', help='The version ID of the object.', required=True)

def main():
    args = parser.parse_args()

    # Load credentials from environment variables.
    credentials_provider = oss.credentials.EnvironmentVariableCredentialsProvider()

    # Load the default SDK configuration and set the credential provider.
    cfg = oss.config.load_default()
    cfg.credentials_provider = credentials_provider
    cfg.region = args.region

    if args.endpoint is not None:
        cfg.endpoint = args.endpoint

    client = oss.Client(cfg)

    # Download the specified version of the object.
    result = client.get_object(oss.GetObjectRequest(
        bucket=args.bucket,
        key=args.key,
        version_id=args.version_id,
    ))

    # Print response metadata.
    print(f'status code: {result.status_code},'
          f' request id: {result.request_id},'
          f' content length: {result.content_length},'
          f' content range: {result.content_range},'
          f' content type: {result.content_type},'
          f' etag: {result.etag},'
          f' last modified: {result.last_modified},'
          f' content md5: {result.content_md5},'
          f' cache control: {result.cache_control},'
          f' content disposition: {result.content_disposition},'
          f' content encoding: {result.content_encoding},'
          f' expires: {result.expires},'
          f' hash crc64: {result.hash_crc64},'
          f' storage class: {result.storage_class},'
          f' object type: {result.object_type},'
          f' version id: {result.version_id},'
          f' tagging count: {result.tagging_count},'
          f' server side encryption: {result.server_side_encryption},'
          f' server side data encryption: {result.server_side_data_encryption},'
          f' next append position: {result.next_append_position},'
          f' expiration: {result.expiration},'
          f' restore: {result.restore},'
          f' process status: {result.process_status},'
          f' delete marker: {result.delete_marker},'
          )

    # Read the object content and save to a local file.
    content = result.body.read()
    with open('./test.txt', 'wb') as f:
        f.write(content)

    print('File saved to test.txt successfully!')

if __name__ == "__main__":
    main()

Replace the following placeholders before running:

Credentials are loaded from the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables. Do not hardcode credentials in your code.

References

• For the complete sample code, see get_object.py.