Copying a Part (SDK for Python)
Function
This API copies a part to a specified bucket. This request must contain the multipart upload ID.
After creating a multipart upload, you can specify the upload ID and upload parts for the multipart upload. Alternatively, you can call this API to copy part or all of an uploaded object as a part.
Assume that you copy a source object and save it as part1. If there is already a part1 before the copy, the new part1 will overwrite the existing part1. Then, only the new part1 can be listed and the old part1 is deleted. Therefore, when using this API, ensure that the target part does not exist or is no longer used, to avoid accidental deletion. The source object keeps unchanged in the entire copy process.
Restrictions
- To copy a part, you must be the bucket owner or have the required permission (obs:object:PutObject in IAM or PutObject in a bucket policy). For details, see Introduction to OBS Access Control, IAM Custom Policies, and Configuring an Object Policy.
- The mapping between OBS regions and endpoints must comply with what is listed in Regions and Endpoints.
- You cannot determine whether a part copy is successful only based on status_code in the HTTP header returned. A 200 response indicates that the server has received the request and starts to process the request. Only when the response body contains ETag, the copy is successful, or the copy fails.
Method
ObsClient.copyPart(bucketName, objectKey, partNumber, uploadId, copySource, copySourceRange, destSseHeader, sourceSseHeader)
Request Parameters
Parameter |
Type |
Mandatory (Yes/No) |
Description |
---|---|---|---|
bucketName |
str |
Yes |
Explanation: Target bucket name Restrictions:
Default value: None |
objectKey |
str |
Yes |
Explanation: Object name. An object is uniquely identified by an object name in a bucket. An object name is a complete path that does not contain the bucket name. For example, if the address for accessing the object is examplebucket.obs.ap-southeast-1.myhuaweicloud.com/folder/test.txt, the object name is folder/test.txt. Value range: The value must contain 1 to 1,024 characters. Default value: None
NOTE:
The object URL is in the following format: https://Bucket name.Domain name/Folder directory level/Object name. If this object is stored in the root directory of the bucket, its URL does not contain the folder directory level. |
partNumber |
int |
Yes |
Explanation: Part number Value range: [1,10000] Default value: None |
uploadId |
str |
Yes |
Explanation: Multipart upload ID, for example, 000001648453845DBB78F2340DD460D8 Value range: The value must contain 32 characters. Default value: None |
copySource |
str |
Yes |
Explanation: Parameter used to specify the source bucket, source object, and source object version ID which can be left blank. It is in the format of SourceBucketName/SourceObjectName?versionId=SourceObjectVersionId. Restrictions:
Default value: None |
copySourceRange |
str |
No |
Explanation: Copy source range. For example, 0-999 indicates the range is from byte 1 to byte 1,000. Value range: Value range: 0 to the object length minus 1. Format: x-y, indicating the range is from byte x+1 to byte y+1 Restrictions: The upper limit of range is the length of the object minus 1. If the specified value exceeds this limit, the length of the object minus 1 is used. Default value: None |
destSseHeader |
No |
Explanation: Server-side encryption header used for encrypting the target object. For details, see Table 2 or Table 3. |
|
sourceSseHeader |
No |
Explanation: Server-side decryption header used for decrypting the source object. For details, see Table 2. |
Parameter |
Type |
Mandatory (Yes/No) |
Description |
---|---|---|---|
encryption |
str |
Yes |
Explanation: SSE-C used for encrypting objects Value range: AES256 Default value: None |
key |
str |
Yes |
Explanation: Key used in SSE-C encryption. It corresponds to the encryption method. For example, if encryption is set to AES256, the key is calculated using the AES-256 algorithm. Value range: The value must contain 32 characters. Default value: None |
Parameter |
Type |
Mandatory (Yes/No) |
Description |
---|---|---|---|
encryption |
str |
Yes |
Explanation: SSE-KMS used for encrypting objects Value range: kms Default value: None |
key |
str |
No |
Explanation: Master key used in SSE-KMS Value range: The following two formats are supported:
In the preceding formats:
Default value:
|
Responses
Type |
Description |
---|---|
Explanation: SDK common results |
Parameter |
Type |
Description |
---|---|---|
status |
int |
Explanation: HTTP status code Value range: A status code is a group of digits ranging from 2xx (indicating successes) to 4xx or 5xx (indicating errors). It indicates the status of a response. For more information, see Status Code. Default value: None |
reason |
str |
Explanation: Reason description. Default value: None |
errorCode |
str |
Explanation: Error code returned by the OBS server. If the value of status is less than 300, this parameter is left blank. Default value: None |
errorMessage |
str |
Explanation: Error message returned by the OBS server. If the value of status is less than 300, this parameter is left blank. Default value: None |
requestId |
str |
Explanation: Request ID returned by the OBS server Default value: None |
indicator |
str |
Explanation: Error indicator returned by the OBS server. Default value: None |
hostId |
str |
Explanation: Requested server ID. If the value of status is less than 300, this parameter is left blank. Default value: None |
resource |
str |
Explanation: Error source (a bucket or an object). If the value of status is less than 300, this parameter is left blank. Default value: None |
header |
list |
Explanation: Response header list, composed of tuples. Each tuple consists of two elements, respectively corresponding to the key and value of a response header. Default value: None |
body |
object |
Explanation: Result content returned after the operation is successful. If the value of status is larger than 300, this parameter is left blank. The value varies with the API being called. For details, see Bucket-Related APIs (SDK for Python) and Object-Related APIs (SDK for Python). Default value: None |
GetResult.body Type |
Description |
---|---|
Explanation: Response to the request for copying a part. For details, see Table 7. |
Parameter |
Type |
Description |
---|---|---|
etag |
str |
Explanation: Base64-encoded 128-bit MD5 digest of a part. ETag is the unique identifier of the part content. It can be used to determine whether the part content is changed. Value range: The value must contain 32 characters. Default value: None |
crc64 |
str |
Explanation: A 64-bit CRC value calculated based on the ECMA-182 standard. It uniquely identifies an object and can be used to check the integrity of the object content. If an object has different CRC64 values when being uploaded and downloaded, its content has been changed. CRC64 reflects changes to the contents of the object, not its metadata. Restrictions:
Value range: A 64-bit CRC value calculated based on the ECMA-182 standard. Default value: None |
lastModified |
str |
Explanation: Time when the last modification was made to the object Restrictions: The time must be in the GMT format, for example, Wed, 25 Mar 2020 02:39:52 GMT. Default value: None |
sseKms |
str |
Explanation: SSE-KMS is used for encrypting objects on the server side. Value range: kms Default value: None |
sseKmsKey |
str |
Explanation: ID of the KMS master key when SSE-KMS is used Value range: Valid value formats are as follows:
In the preceding formats:
Default value:
|
sseC |
str |
Explanation: Algorithm used to encrypt and decrypt objects with SSE-C Value range: AES256 Default value: None |
sseCKeyMd5 |
str |
Explanation: MD5 value of the key for encrypting objects when SSE-C is used. This value is used to check whether any error occurs during the transmission of the key. Restrictions: The value is encrypted by MD5 and then encoded by Base64, for example, 4XvB3tbNTN+tIEVa0/fGaQ==. Default value: None |
Code Examples
This example copies parts from one bucket to another.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 |
from obs import ObsClient import os import traceback # Obtain an AK and SK pair using environment variables or import the AK and SK pair in other ways. Using hard coding may result in leakage. # Obtain an AK and SK pair on the management console. For details, see https://support.huaweicloud.com/intl/en-us/usermanual-ca/ca_01_0003.html. ak = os.getenv("AccessKeyID") sk = os.getenv("SecretAccessKey") # (Optional) If you use a temporary AK and SK pair and a security token to access OBS, obtain them from environment variables. security_token = os.getenv("SecurityToken") # Set server to the endpoint corresponding to the bucket. Here uses CN-Hong Kong as an example. Replace it with the one in use. server = "https://obs.ap-southeast-1.myhuaweicloud.com" # Create an obsClient instance. # If you use a temporary AK and SK pair and a security token to access OBS, you must specify security_token when creating an instance. obsClient = ObsClient(access_key_id=ak, secret_access_key=sk, server=server) try: bucketName = "examplebucket" objectKey = "objectname" # Specify the part number, which ranges from 1 to 10,000 partNumber = "your partNumber" # Specify the ID of the multipart upload. uploadId = "your uploadid" # Specify the source bucket, source object, and source object version ID (optional). The format is source-bucket-name/source-object-name?versionId=source-object-versionId. copySource = 'sourcebucketname/sourceobjectkey' # [Optional] Specify the copy scope in the format of x-y. Value range: [0, source-object-length – 1]. # copySourceRange = '0-15' # Copy the part to the specified bucket using the multipart upload ID. resp = obsClient.copyPart(bucketName, objectKey, partNumber, uploadId, copySource) # If status code 2xx is returned, the API is called successfully. Otherwise, the API call fails. if resp.status < 300: print('Copy Part Succeeded') print('requestId:', resp.requestId) print('etagValue:', resp.body.etagValue) print('modifiedDate:', resp.body.modifiedDate) else: print('Copy Part Failed') print('requestId:', resp.requestId) print('errorCode:', resp.errorCode) print('errorMessage:', resp.errorMessage) except: print('Copy Part Failed') print(traceback.format_exc()) |
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