Query object metadata (OSS SDK for Python 1.0)
By default, when you call the HeadObject operation on an Object Storage Service (OSS) object in a versioning-enabled bucket, the metadata of only the current version of the object is returned.
If the current version of the object is a delete marker, OSS returns 404 Not Found. If you specify a version ID in the request, OSS returns the metadata of the specified version of the object.
Notes
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In this topic, the public endpoint of the China (Hangzhou) region is used. If you want to access OSS from other Alibaba Cloud services in the same region as OSS, use an internal endpoint. For more information about OSS regions and endpoints, see Regions and endpoints.
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In this topic, access credentials are obtained from environment variables. For more information about how to configure access credentials, see Configure access credentials using OSS SDK for Python 1.0.
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This topic demonstrates creating an OSSClient instance with an OSS endpoint. For alternative configurations, such as using a custom domain or authenticating with credentials from Security Token Service (STS), see Initialization.
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To query object metadata, you must have the
oss:GetObjectpermission. For more information, see Grant a custom policy.
Examples
The following sample code provides an example on how to query the metadata of an object:
# -*- coding: utf-8 -*-
import oss2
from oss2.credentials import EnvironmentVariableCredentialsProvider
# Obtain access credentials from environment variables. Before you run the sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are configured.
auth = oss2.ProviderAuthV4(EnvironmentVariableCredentialsProvider())
# Specify the endpoint of the region in which the bucket is located. For example, if the bucket is located in the China (Hangzhou) region, set the endpoint to https://oss-cn-hangzhou.aliyuncs.com.
endpoint = "https://oss-cn-hangzhou.aliyuncs.com"
# Specify the ID of the region that maps to the endpoint. Example: cn-hangzhou. This parameter is required if you use the signature algorithm V4.
region = "cn-hangzhou"
# Specify the name of your bucket.
bucket = oss2.Bucket(auth, endpoint, "yourBucketName", region=region)
# Specify the versionId field in param.
params = dict()
params['versionId'] = 'yourObjectVersionId'
# Query part of the metadata of the object.
simplifiedmeta = bucket.get_object_meta("yourObjectName", params=params)
print(simplifiedmeta.headers['Last-Modified'])
print(simplifiedmeta.headers['Content-Length'])
print(simplifiedmeta.headers['ETag'])
# Query all metadata of the object.
objectmeta = bucket.head_object("yourObjectName", params=params)
print(objectmeta.headers['Content-Type'])
print(objectmeta.headers['Last-Modified'])
print(objectmeta.headers['x-oss-object-type'])References
For more information about the API operations that you can call to query the metadata of an object, see HeadObject and GetObjectMeta.