Uploading a Part (SDK for Python)

Updated on 2025-02-26 GMT+08:00

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Function

After a multipart upload is initiated, this API uploads a part to a specified bucket. In the upload request, the multipart upload ID must be included. Except for the part lastly being uploaded whose size ranges from 0 to 5 GB, sizes of the other parts range from 100 KB to 5 GB. Part numbers can be any number from 1 to 10,000.

When uploading a part, you must specify its upload ID and part number. A part number uniquely identifies a part and its position in the object you are uploading. If you upload a new part with the same part number as that of a previous part, the previously uploaded part will be overwritten. Whenever you upload a part, OBS returns the ETag header in the response. For each part upload task, you must record the part number and ETag value. These values are required in subsequent requests for you to complete a multipart upload.

Restrictions

To upload 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.
After initiating a multipart upload and uploading one or more parts, you must assemble the parts or abort the multipart upload. Only after that can OBS stops billing you for storing the uploaded parts.
partNumber in a multipart upload must be unique. When the same partNumber of the same object is concurrently uploaded, last write wins policy is applied. The time of last write is defined as the time when the part metadata is created. To ensure data accuracy, the client must be locked to ensure concurrent uploads of the same part of the same object. Concurrent uploads for different parts of the same object do not need to be locked.

Method

ObsClient.uploadPart(bucketName, objectKey, partNumber, uploadId, object, isFile, partSize, offset, sseHeader, isAttachMd5, md5, progressCallback, autoClose, extensionHeaders)

Request Parameters

**Table 1** List of request parameters
Parameter	Type	Mandatory (Yes/No)	Description
bucketName	str	Yes	Explanation: Bucket name Restrictions: A bucket name must be unique across all accounts and regions. A bucket name: Must be 3 to 63 characters long and start with a digit or letter. Lowercase letters, digits, hyphens (-), and periods (.) are allowed. Cannot be formatted as an IP address. Cannot start or end with a hyphen (-) or period (.). Cannot contain two consecutive periods (..), for example, my..bucket. Cannot contain periods (.) and hyphens (-) adjacent to each other, for example, my-.bucket or my.-bucket. If you repeatedly create buckets of the same name in the same region, no error will be reported and the bucket attributes comply with those set in the first creation request. 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 which can be returned by initiating a multipart upload, for example, 000001648453845DBB78F2340DD460D8 Restrictions: The value must contain 32 characters. Default value: None
object	str or readable object	Yes	Explanation: Part content to be uploaded Value range: A string or a readable object NOTE: If object is a readable object that contains the read attribute, data is read from the readable object. Otherwise, the object content is a string. Default value: None
isFile	bool	No	Explanation: Whether object indicates the file path. Value range: True: object indicates the file path. False: object does not indicate the file path. Default value: False
offset	int	No	Explanation: Start offset of a part in the source file Value range: A non-negative integer not exceeding the size of the object to be uploaded, in bytes Default value: 0
partSize	int	No	Explanation: Part size Restrictions: Except for the last uploaded part, all parts must be larger than 100 KB. Part sizes will not be verified during upload because whether an uploaded part is the last one cannot be determined. Their sizes will be verified when being assembled. The minimum part size supported by an OBS 3.0 bucket is 100 KB, and that supported by an OBS 2.0 bucket is 5 MB. Value range: The value ranges from 100 KB to 5 GB, in bytes. Default value: 102400
sseHeader	SseCHeader	No	Explanation: Server-side encryption header. For details, see Table 2. Default value: None
isAttachMd5	bool	No	Explanation: Whether to automatically calculate the MD5 value of the data to be uploaded. Restrictions: If isAttachMd5 and md5 are used at the same time, isAttachMd5 is invalid. Value range: True: The MD5 value of the data to be uploaded is automatically calculated. False: The MD5 value of the data to be uploaded is not automatically calculated. Default value: False
md5	str	No	Explanation: Base64-encoded MD5 value of the part to be uploaded, which uniquely identifies the content of the uploaded part and can be used to identify whether the object content is changed. Restrictions: If isAttachMd5 and md5 are used at the same time, isAttachMd5 is invalid. Value range: The value must contain 32 characters. Default value: None
progressCallback	callable	No	Explanation: Callback function for obtaining the upload progress Default value: None NOTE: This callback function contains the following parameters in sequence: number of uploaded bytes, total bytes, and used time (in seconds).
autoClose	bool	No	Explanation: Whether to automatically close data streams after the upload is complete Value range: True: The data stream is automatically closed. False: The data stream is not automatically closed. Default value: True
extensionHeaders	dict	No	Explanation: Extension headers. Value range: See User-defined Header (SDK for Python). Default value: None

**Table 2** SseCHeader
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

Responses

**Table 3** List of returned results
Type	Description
GetResult	Explanation: SDK common results

**Table 4** GetResult
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, the value of body is null. 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

**Table 5** GetResult.body
GetResult.body Type	Description
UploadPartResponse	Explanation: Response to the request for uploading a part

**Table 6** UploadPartResponse
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
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: regionID:domainID:key/key_id key_id In the preceding formats: regionID indicates the ID of the region where the key is used. You can obtain it from Regions and Endpoints. domainID indicates the ID of the account that the key is for. To obtain it, see How Do I Get My Account ID and IAM User ID? (SDK for Python) key_id indicates the ID of the key created on Data Encryption Workshop (DEW). To obtain it, see Viewing a CMK. Default value: If this parameter is not specified, the default master key will be used. If there is no such a default master key, OBS will create one and use it by default.
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 uploads a part.

    
     
       
       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. CN-Hong Kong is used here 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"
    # Specify the name of the object to be uploaded to the bucket.
    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 content of the part to be uploaded as a string or readable object.
    object = 'Hello OBS'
    # Specify whether object indicates the file path. The default value is False.
    isFile = False
    # Specify the start offset (in bytes) of a part in the source file. The default value is 0.
    offset = 0
    # Specify the size (in bytes) of a part in the source file. The default value is the file size minus offset.
    partSize = 9 * 1024 * 1024
    # Specify whether to automatically calculate the MD5 value of the data to be uploaded. The default value is False.
    isAttachMd5 = True
    # Upload the part to a specified bucket using the multipart upload ID.
    resp = obsClient.uploadPart(bucketName, objectKey, partNumber, uploadId, object, isFile, partSize,
                                offset, isAttachMd5=isAttachMd5)

    # If status code 2xx is returned, the API is called successfully. Otherwise, the API call fails.
    if resp.status < 300:
        print('Upload Part Succeeded')
        print('requestId:', resp.requestId)
        print('etag:', resp.body.etag)
    else:
        print('Upload Part Failed')
        print('requestId:', resp.requestId)
        print('errorCode:', resp.errorCode)
        print('errorMessage:', resp.errorMessage)
except:
    print('Upload Part Failed')
    print(traceback.format_exc())

      

    
   

Helpful Links

Parent topic: APIs Related to Multipart Upload (SDK for Python)

Previous topic: Initiating a Multipart Upload (SDK for Python)

Next topic: Listing Uploaded Parts (SDK for Python)

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