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    Object Storage Service:List objects

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    Object Storage Service:List objects

    Last Updated:Nov 10, 2024

    This topic describes how to list objects in a versioned bucket. You can list all objects, a specified number of objects, and objects whose names contain a specified prefix.

    Usage notes

    • 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, endpoints and open ports.

    • In this topic, access credentials are obtained from environment variables. For more information about how to configure access credentials, see Configure access credentials.

    • In this topic, an OSSClient instance is created by using an OSS endpoint. If you want to create an OSSClient instance by using custom domain names or Security Token Service (STS), see Initialization.

    • To list objects, you must have the oss:ListObjectVersions permission. For more information, see Attach a custom policy to a RAM user.

    List the versions of all objects in a bucket

    The following code provides an example on how to list the versions of all objects including delete markers in a specified bucket:

    # -*- 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)


# Call the list_object_versions operation to list the versions of objects in a versioning-enabled bucket. 
# List the versions of all objects, including delete markers in the bucket. 
result = bucket.list_object_versions()

# List the versions of all objects in the bucket. 
next_key_marker = None
next_versionid_marker = None
while True:
    result = bucket.list_object_versions(key_marker=next_key_marker, versionid_marker=next_versionid_marker)

    # Display the versions of the listed objects. 
    for version_info in result.versions:
        print('version_info.versionid:', version_info.versionid)
        print('version_info.key:', version_info.key)
        print('version_info.is_latest:', version_info.is_latest)

    # Display the versions of the listed delete markers. 
    for del_maker_Info in result.delete_marker:
        print('del_maker.key:', del_maker_Info.key)
        print('del_maker.versionid:', del_maker_Info.versionid)
        print('del_maker.is_latest:', del_maker_Info.is_latest)

    is_truncated = result.is_truncated

    # Check whether all versions of all objects in the bucket are listed. If the versions of all objects are incompletely listed, the list operation continues. If the versions of all objects are completely listed, the list operation stops. 
    if is_truncated:
        next_key_marker = result.next_key_marker
        next_versionid_marker = result.next_versionid_marker
    else:
        break

    List the versions of objects whose names contain a specified prefix

    The following code provides an example on how to list the versions of objects whose names contain a specified prefix:

    # -*- 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)

# Call the list_object_versions operation to list the versions of objects in a versioning-enabled bucket. 
# List the versions of all objects, including delete markers in the bucket. 
result = bucket.list_object_versions()

# List the versions of objects whose names contain the test- prefix. 
prefix = 'test-'
next_key_marker = None
next_versionid_marker = None
while True:
    result = bucket.list_object_versions(prefix=prefix, key_marker=next_key_marker, versionid_marker=next_versionid_marker)

    # Display the versions of the listed objects. 
    for version_info in result.versions:
        print('version_info.versionid:', version_info.versionid)
        print('version_info.key:', version_info.key)
        print('version_info.is_latest:', version_info.is_latest)

    # Display the versions of the listed delete markers. 
    for del_maker_Info in result.delete_marker:
        print('del_maker.key:', del_maker_Info.key)
        print('del_maker.versionid:', del_maker_Info.versionid)
        print('del_maker.is_latest:', del_maker_Info.is_latest)

    is_truncated = result.is_truncated

    # Check whether all versions of all objects in the bucket are listed. If the versions of all objects are incompletely listed, the list operation continues. If the versions of all objects are completely listed, the list operation stops. 
    if is_truncated:
        next_key_marker = result.next_key_marker
        next_versionid_marker = result.next_versionid_marker
    else:
        break

    List the versions of a specified number of objects

    The following code provides an example on how to list the versions of a specific number of objects:

    # -*- 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)

# Call the list_object_versions operation to list the versions of objects in a versioning-enabled bucket. 
# List the versions of all objects, including delete markers in the bucket. 
result = bucket.list_object_versions()

# List up to 200 object versions. 
max_keys = 200

result = bucket.list_object_versions(max_keys=max_keys)

# Display the versions of the listed objects. 
for version_info in result.versions:
    print('version_info.versionid:', version_info.versionid)
    print('version_info.key:', version_info.key)
    print('version_info.is_latest:', version_info.is_latest)

# Display the versions of the listed delete markers. 
for del_maker_Info in result.delete_marker:
    print('del_maker.key:', del_maker_Info.key)
    print('del_maker.versionid:', del_maker_Info.versionid)
    print('del_maker.is_latest:', del_maker_Info.is_latest)

# Check whether the listing is truncated. 
# If the number of objects in the bucket is greater than 200, the value of is_truncated is True, which indicates that the listing is truncated. If the number of objects in the bucket is smaller than 200, the value of is_truncated is False, which indicates that the listing is not truncated. 
print('is truncated', result.is_truncated)

    List objects by directory

    OSS uses a flat structure to store objects. A directory is a zero-byte object whose name ends with a forward slash (/). You can upload and download a directory. By default, an object whose name ends with a forward slash (/) is displayed as a directory in the OSS console.

    You can specify the delimiter and prefix parameters in the request to list objects by directory.

    • If you set prefix to a directory name in the request, objects and subdirectories whose names contain the prefix are listed.

    • If you specify a prefix and set delimiter to a forward slash (/) in the request, objects and subdirectories whose names start with the specified prefix in the directory are listed. Each subdirectory is listed as a single result element in CommonPrefixes. The objects and directories in these subdirectories are not listed.

    Example: A bucket named examplebucket contains the following objects: oss.jpg, fun/test.jpg, fun/movie/001.avi, and fun/movie/007.txt. The forward slash (/) is used as the delimiter for the directory. The following structure shows the objects and the directories in the examplebucket bucket.

    examplebucket           
 └── oss.jpg
 └── fun               
      └── test.jpg
      └── movie
           └── 001.avi
           └── 007.txt

    The following examples describe how to list objects in simulated directories.

    • List the versions of objects within the root directory of a bucket

      The following code provides an example on how to list the versions of objects in the root directory of a bucket:

      # -*- 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)

# Call the list_object_versions operation to list the versions of objects in a versioning-enabled bucket. 
# List the versions of all objects, including delete markers in the bucket. 
result = bucket.list_object_versions()

# Specify the forward slash (/) as the delimiter. 
delimiter = "/"
next_key_marker = None
next_versionid_marker = None
while True:
    result = bucket.list_object_versions(delimiter=delimiter, key_marker=next_key_marker, versionid_marker=next_versionid_marker)

    # Display the versions of the listed objects. 
    for version_info in result.versions:
        print('version_info.versionid:', version_info.versionid)
        print('version_info.key:', version_info.key)
        print('version_info.is_latest:', version_info.is_latest)

    # Display the versions of the listed delete markers. 
    for del_maker_Info in result.delete_marker:
        print('del_maker.key:', del_maker_Info.key)
        print('del_maker.versionid:', del_maker_Info.versionid)
        print('del_maker.is_latest:', del_maker_Info.is_latest)

    # Display the directories whose names end with a forward slash (/). 
    for common_prefix in result.common_prefix:
        print("common_prefix:", common_prefix)

    is_truncated = result.is_truncated

    # Check whether all versions of all objects in the bucket are listed. If the versions of all objects are incompletely listed, the list operation continues. If the versions of all objects are completely listed, the list operation stops. 
    if is_truncated:
        next_key_marker = result.next_key_marker
        next_versionid_marker = result.next_versionid_marker
    else:
        break

      Result

      ('version_info.versionid:', 'CAEQEhiBgMCw8Y7FqBciIGIzMDE3MTEzOWRiMDRmZmFhMmRlMjljZWI0MWU4****')
('version_info.key:', 'oss.jpg')
('version_info.is_latest:', True)
('common_prefix:', 'fun/')

    • List the objects and subdirectories in a specified directory

      The following code provides an example on how to list the objects and the subdirectories in a directory of a bucket:

      # -*- 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)

# Call the list_object_versions operation to list the versions of objects in a versioning-enabled bucket. 
# List the versions of all objects including delete markers in a bucket. 
result = bucket.list_object_versions()

# Set delimiter to a forward slash (/) and prefix to fun/. 
prefix = "fun/"
delimiter = "/"
next_key_marker = None
next_versionid_marker = None
while True:
    result = bucket.list_object_versions(prefix=prefix, delimiter=delimiter, key_marker=next_key_marker, versionid_marker=next_versionid_marker)

    # Display the versions of the listed objects. 
    for version_info in result.versions:
        print('version_info.versionid:', version_info.versionid)
        print('version_info.key:', version_info.key)
        print('version_info.is_latest:', version_info.is_latest)

    # Display the versions of the listed delete markers. 
    for del_maker_Info in result.delete_marker:
        print('del_maker.key:', del_maker_Info.key)
        print('del_maker.versionid:', del_maker_Info.versionid)
        print('del_maker.is_latest:', del_maker_Info.is_latest)

    # Display the directories whose names end with a forward slash (/). 
    for common_prefix in result.common_prefix:
        print("common_prefix:", common_prefix)

    is_truncated = result.is_truncated

    # Check whether all versions of all objects in the bucket are listed. If the versions of all objects are incompletely listed, the list operation continues. If the versions of all objects are completely listed, the list operation stops. 
    if is_truncated:
        next_key_marker = result.next_key_marker
        next_versionid_marker = result.next_versionid_marker
    else:
        break

      Result

      ('version_info.versionid:', 'CAEQFRiBgMCh9JDkrxciIGE3OTNkYzFhYTc2YzQzOTQ4Y2MzYjg2YjQ4ODg*****')
('version_info.key:', 'fun/test.jpg')
('version_info.is_latest:', True)
('commonPrefix:', 'fun/movie/')

    References

    For more information about the API operation that you can call to list objects, see ListObjectVersions (GetBucketVersions).