S3 / Client / get_object_attributes

get_object_attributes#

S3.Client.get_object_attributes(**kwargs)#

Retrieves all the metadata from an object without returning the object itself. This action is useful if you’re interested only in an object’s metadata. To use GetObjectAttributes, you must have READ access to the object.

GetObjectAttributes combines the functionality of HeadObject and ListParts. All of the data returned with each of those individual calls can be returned with a single call to GetObjectAttributes.

If you encrypt an object by using server-side encryption with customer-provided encryption keys (SSE-C) when you store the object in Amazon S3, then when you retrieve the metadata from the object, you must use the following headers:

  • x-amz-server-side-encryption-customer-algorithm

  • x-amz-server-side-encryption-customer-key

  • x-amz-server-side-encryption-customer-key-MD5

For more information about SSE-C, see Server-Side Encryption (Using Customer-Provided Encryption Keys) in the Amazon S3 User Guide.

Note

  • Encryption request headers, such as x-amz-server-side-encryption, should not be sent for GET requests if your object uses server-side encryption with Amazon Web Services KMS keys stored in Amazon Web Services Key Management Service (SSE-KMS) or server-side encryption with Amazon S3 managed keys (SSE-S3). If your object does use these types of keys, you’ll get an HTTP 400 Bad Request error.

  • The last modified property in this case is the creation date of the object.

Consider the following when using request headers:

  • If both of the If-Match and If-Unmodified-Since headers are present in the request as follows, then Amazon S3 returns the HTTP status code 200 OK and the data requested:

    • If-Match condition evaluates to true.

    • If-Unmodified-Since condition evaluates to false.

  • If both of the If-None-Match and If-Modified-Since headers are present in the request as follows, then Amazon S3 returns the HTTP status code 304 Not Modified:

    • If-None-Match condition evaluates to false.

    • If-Modified-Since condition evaluates to true.

For more information about conditional requests, see RFC 7232.

Permissions

The permissions that you need to use this operation depend on whether the bucket is versioned. If the bucket is versioned, you need both the s3:GetObjectVersion and s3:GetObjectVersionAttributes permissions for this operation. If the bucket is not versioned, you need the s3:GetObject and s3:GetObjectAttributes permissions. For more information, see Specifying Permissions in a Policy in the Amazon S3 User Guide. If the object that you request does not exist, the error Amazon S3 returns depends on whether you also have the s3:ListBucket permission.

  • If you have the s3:ListBucket permission on the bucket, Amazon S3 returns an HTTP status code 404 Not Found (“no such key”) error.

  • If you don’t have the s3:ListBucket permission, Amazon S3 returns an HTTP status code 403 Forbidden (“access denied”) error.

The following actions are related to GetObjectAttributes:

See also: AWS API Documentation

Request Syntax

response = client.get_object_attributes(
    Bucket='string',
    Key='string',
    VersionId='string',
    MaxParts=123,
    PartNumberMarker=123,
    SSECustomerAlgorithm='string',
    SSECustomerKey='string',
    RequestPayer='requester',
    ExpectedBucketOwner='string',
    ObjectAttributes=[
        'ETag'|'Checksum'|'ObjectParts'|'StorageClass'|'ObjectSize',
    ]
)
Parameters:

  • Bucket (string) –

    [REQUIRED]

    The name of the bucket that contains the object.

    When using this action with an access point, you must direct requests to the access point hostname. The access point hostname takes the form AccessPointName-AccountId.s3-accesspoint.*Region*.amazonaws.com. When using this action with an access point through the Amazon Web Services SDKs, you provide the access point ARN in place of the bucket name. For more information about access point ARNs, see Using access points in the Amazon S3 User Guide.

    When you use this action with Amazon S3 on Outposts, you must direct requests to the S3 on Outposts hostname. The S3 on Outposts hostname takes the form AccessPointName-AccountId.outpostID.s3-outposts.Region.amazonaws.com. When you use this action with S3 on Outposts through the Amazon Web Services SDKs, you provide the Outposts access point ARN in place of the bucket name. For more information about S3 on Outposts ARNs, see What is S3 on Outposts? in the Amazon S3 User Guide.

  • Key (string) –

    [REQUIRED]

    The object key.

  • VersionId (string) – The version ID used to reference a specific version of the object.

  • MaxParts (integer) – Sets the maximum number of parts to return.

  • PartNumberMarker (integer) – Specifies the part after which listing should begin. Only parts with higher part numbers will be listed.

  • SSECustomerAlgorithm (string) – Specifies the algorithm to use when encrypting the object (for example, AES256).

  • SSECustomerKey (string) – Specifies the customer-provided encryption key for Amazon S3 to use in encrypting data. This value is used to store the object and then it is discarded; Amazon S3 does not store the encryption key. The key must be appropriate for use with the algorithm specified in the x-amz-server-side-encryption-customer-algorithm header.

  • SSECustomerKeyMD5 (string) –

    Specifies the 128-bit MD5 digest of the encryption key according to RFC 1321. Amazon S3 uses this header for a message integrity check to ensure that the encryption key was transmitted without error.

    Please note that this parameter is automatically populated if it is not provided. Including this parameter is not required

  • RequestPayer (string) – Confirms that the requester knows that they will be charged for the request. Bucket owners need not specify this parameter in their requests. For information about downloading objects from Requester Pays buckets, see Downloading Objects in Requester Pays Buckets in the Amazon S3 User Guide.

  • ExpectedBucketOwner (string) – The account ID of the expected bucket owner. If the bucket is owned by a different account, the request fails with the HTTP status code 403 Forbidden (access denied).

  • ObjectAttributes (list) –

    [REQUIRED]

    Specifies the fields at the root level that you want returned in the response. Fields that you do not specify are not returned.

    • (string) –

Return type:

dict

Returns:

Response Syntax

{
    'DeleteMarker': True|False,
    'LastModified': datetime(2015, 1, 1),
    'VersionId': 'string',
    'RequestCharged': 'requester',
    'ETag': 'string',
    'Checksum': {
        'ChecksumCRC32': 'string',
        'ChecksumCRC32C': 'string',
        'ChecksumSHA1': 'string',
        'ChecksumSHA256': 'string'
    },
    'ObjectParts': {
        'TotalPartsCount': 123,
        'PartNumberMarker': 123,
        'NextPartNumberMarker': 123,
        'MaxParts': 123,
        'IsTruncated': True|False,
        'Parts': [
            {
                'PartNumber': 123,
                'Size': 123,
                'ChecksumCRC32': 'string',
                'ChecksumCRC32C': 'string',
                'ChecksumSHA1': 'string',
                'ChecksumSHA256': 'string'
            },
        ]
    },
    'StorageClass': 'STANDARD'|'REDUCED_REDUNDANCY'|'STANDARD_IA'|'ONEZONE_IA'|'INTELLIGENT_TIERING'|'GLACIER'|'DEEP_ARCHIVE'|'OUTPOSTS'|'GLACIER_IR'|'SNOW',
    'ObjectSize': 123
}

Response Structure

  • (dict) –

    • DeleteMarker (boolean) –

      Specifies whether the object retrieved was ( true) or was not ( false) a delete marker. If false, this response header does not appear in the response.

    • LastModified (datetime) –

      The creation date of the object.

    • VersionId (string) –

      The version ID of the object.

    • RequestCharged (string) –

      If present, indicates that the requester was successfully charged for the request.

    • ETag (string) –

      An ETag is an opaque identifier assigned by a web server to a specific version of a resource found at a URL.

    • Checksum (dict) –

      The checksum or digest of the object.

      • ChecksumCRC32 (string) –

        The base64-encoded, 32-bit CRC32 checksum of the object. This will only be present if it was uploaded with the object. With multipart uploads, this may not be a checksum value of the object. For more information about how checksums are calculated with multipart uploads, see Checking object integrity in the Amazon S3 User Guide.

      • ChecksumCRC32C (string) –

        The base64-encoded, 32-bit CRC32C checksum of the object. This will only be present if it was uploaded with the object. With multipart uploads, this may not be a checksum value of the object. For more information about how checksums are calculated with multipart uploads, see Checking object integrity in the Amazon S3 User Guide.

      • ChecksumSHA1 (string) –

        The base64-encoded, 160-bit SHA-1 digest of the object. This will only be present if it was uploaded with the object. With multipart uploads, this may not be a checksum value of the object. For more information about how checksums are calculated with multipart uploads, see Checking object integrity in the Amazon S3 User Guide.

      • ChecksumSHA256 (string) –

        The base64-encoded, 256-bit SHA-256 digest of the object. This will only be present if it was uploaded with the object. With multipart uploads, this may not be a checksum value of the object. For more information about how checksums are calculated with multipart uploads, see Checking object integrity in the Amazon S3 User Guide.

    • ObjectParts (dict) –

      A collection of parts associated with a multipart upload.

      • TotalPartsCount (integer) –

        The total number of parts.

      • PartNumberMarker (integer) –

        The marker for the current part.

      • NextPartNumberMarker (integer) –

        When a list is truncated, this element specifies the last part in the list, as well as the value to use for the PartNumberMarker request parameter in a subsequent request.

      • MaxParts (integer) –

        The maximum number of parts allowed in the response.

      • IsTruncated (boolean) –

        Indicates whether the returned list of parts is truncated. A value of true indicates that the list was truncated. A list can be truncated if the number of parts exceeds the limit returned in the MaxParts element.

      • Parts (list) –

        A container for elements related to a particular part. A response can contain zero or more Parts elements.

        • (dict) –

          A container for elements related to an individual part.

          • PartNumber (integer) –

            The part number identifying the part. This value is a positive integer between 1 and 10,000.

          • Size (integer) –

            The size of the uploaded part in bytes.

          • ChecksumCRC32 (string) –

            This header can be used as a data integrity check to verify that the data received is the same data that was originally sent. This header specifies the base64-encoded, 32-bit CRC32 checksum of the object. For more information, see Checking object integrity in the Amazon S3 User Guide.

          • ChecksumCRC32C (string) –

            The base64-encoded, 32-bit CRC32C checksum of the object. This will only be present if it was uploaded with the object. With multipart uploads, this may not be a checksum value of the object. For more information about how checksums are calculated with multipart uploads, see Checking object integrity in the Amazon S3 User Guide.

          • ChecksumSHA1 (string) –

            The base64-encoded, 160-bit SHA-1 digest of the object. This will only be present if it was uploaded with the object. With multipart uploads, this may not be a checksum value of the object. For more information about how checksums are calculated with multipart uploads, see Checking object integrity in the Amazon S3 User Guide.

          • ChecksumSHA256 (string) –

            The base64-encoded, 256-bit SHA-256 digest of the object. This will only be present if it was uploaded with the object. With multipart uploads, this may not be a checksum value of the object. For more information about how checksums are calculated with multipart uploads, see Checking object integrity in the Amazon S3 User Guide.

    • StorageClass (string) –

      Provides the storage class information of the object. Amazon S3 returns this header for all objects except for S3 Standard storage class objects.

      For more information, see Storage Classes.

    • ObjectSize (integer) –

      The size of the object in bytes.

Exceptions

  • S3.Client.exceptions.NoSuchKey