How to list objects by using OSS SDK for Python 2.0 - Object Storage Service: Central de Documentação do Alibaba Cloud

Este tópico descreve como listar todos os objetos em um bucket com o SDK do Object Storage Service (OSS) para Python.

Notas de uso

O código de exemplo deste tópico usa o ID da região cn-hangzhou, referente à região China (Hangzhou). Por padrão, utilize um endpoint público para acessar os recursos de um bucket. Para acessar os recursos do bucket com outros serviços da Alibaba Cloud na mesma região do bucket, use um endpoint interno. Para obter mais informações sobre as regiões e os endpoints do OSS, consulte Regions and endpoints.
Para listar objetos, é necessária a permissão oss:ListObjects. Para obter mais informações, consulte Grant a custom policy.

Código de exemplo

O exemplo de código a seguir mostra como chamar a operação ListObjectsV2 para listar todos os objetos em um bucket:

import argparse
import alibabacloud_oss_v2 as oss

# Create a command line parameter parser.
parser = argparse.ArgumentParser(description="list objects v2 sample")
# Specify the --region parameter, which specifies the region in which the bucket is located. This command line parameter is required.
parser.add_argument('--region', help='The region in which the bucket is located.', required=True)
# Specify the --bucket parameter, which specifies the name of the bucket. This command line parameter is required.
parser.add_argument('--bucket', help='The name of the bucket.', required=True)
# Specify the --endpoint parameter, which specifies the endpoint that other services can use to access OSS. This command line parameter is optional.
parser.add_argument('--endpoint', help='The domain names that other services can use to access OSS')

def main():
    args = parser.parse_args()  # Parse the command line parameters.

    # Obtain access credentials from environment variables for authentication.
    credentials_provider = oss.credentials.EnvironmentVariableCredentialsProvider()

    # Load the default configurations of the SDK and specify the credential provider.
    cfg = oss.config.load_default()
    cfg.credentials_provider = credentials_provider
    # Set the region in the configuration to the one specified in the command line.
    cfg.region = args.region
    # If the endpoint parameter is provided, specify the endpoint.
    if args.endpoint is not None:
        cfg.endpoint = args.endpoint

    # Use the configurations to create an OSSClient instance.
    client = oss.Client(cfg)

    # Create a paginator to allow the ListObjectsV2 operation to list objects.
    paginator = client.list_objects_v2_paginator()

    # Traverse each page of the listed objects.
    for page in paginator.iter_page(oss.ListObjectsV2Request(
            bucket=args.bucket
        )
    ):
        # Traverse each object on each page.
        for o in page.contents:
            # Display the name, size, and last modified time of the object.
            print(f'Object: {o.key}, {o.size}, {o.last_modified}')

if __name__ == "__main__":
    main() # Specify the entry points in the main function of the script when the script is directly run.

Cenários comuns

Listar todos os objetos em um diretório específico

Para listar os objetos de um diretório específico, use o parâmetro prefix. A resposta incluirá o nome, o tamanho e a data da última modificação de cada item.

import argparse
import alibabacloud_oss_v2 as oss

# Create a command line parameter parser.
parser = argparse.ArgumentParser(description="list objects v2 sample")
# Specify the --region parameter, which specifies the region in which the bucket is located. This command line parameter is required.
parser.add_argument('--region', help='The region in which the bucket is located.', required=True)
# Specify the --bucket parameter, which specifies the name of the bucket. This command line parameter is required.
parser.add_argument('--bucket', help='The name of the bucket.', required=True)
# Specify the --endpoint parameter, which specifies the endpoint that other services can use to access OSS. This command line parameter is optional.
parser.add_argument('--endpoint', help='The domain names that other services can use to access OSS')

def main():
    args = parser.parse_args()  # Parse the command line parameters.

    # Obtain access credentials from environment variables for authentication.
    credentials_provider = oss.credentials.EnvironmentVariableCredentialsProvider()

    # Load the default configurations of the SDK and specify the credential provider.
    cfg = oss.config.load_default()
    cfg.credentials_provider = credentials_provider
    # Set the region in the configuration to the one specified in the command line.
    cfg.region = args.region
    # If the endpoint parameter is provided, specify the endpoint.
    if args.endpoint is not None:
        cfg.endpoint = args.endpoint

    # Use the configurations to create an OSSClient instance.
    client = oss.Client(cfg)

    # Create a paginator to allow the ListObjectsV2 operation to list objects.
    paginator = client.list_objects_v2_paginator()

    # Traverse each page of the listed objects.
    for page in paginator.iter_page(oss.ListObjectsV2Request(
            bucket=args.bucket,
            prefix="exampledir/", # Set the prefix parameter to exampledir/ to list all objects in the exampledir/ directory.
        )
    ):
        # Traverse each object on each page.
        for o in page.contents:
            # Display the name, size, and last modified time of the object.
            print(f'Object: {o.key}, Size: {o.size}, Last_modified: {o.last_modified}')

if __name__ == "__main__":
    main() # Specify the entry points in the main function of the script when the script is directly run.

Listar objetos cujos nomes contêm um prefixo específico

Defina o parâmetro prefix para filtrar objetos cujo nome contenha um termo específico. A listagem exibirá o nome, o tamanho e a data da última modificação dos itens correspondentes.

import argparse
import alibabacloud_oss_v2 as oss

# Create a command line parameter parser.
parser = argparse.ArgumentParser(description="list objects v2 sample")
# Specify the --region parameter, which specifies the region in which the bucket is located. This command line parameter is required.
parser.add_argument('--region', help='The region in which the bucket is located.', required=True)
# Specify the --bucket parameter, which specifies the name of the bucket. This command line parameter is required.
parser.add_argument('--bucket', help='The name of the bucket.', required=True)
# Specify the --endpoint parameter, which specifies the endpoint that other services can use to access OSS. This command line parameter is optional.
parser.add_argument('--endpoint', help='The domain names that other services can use to access OSS')

def main():
    args = parser.parse_args()  # Parse the command line parameters.

    # Obtain access credentials from environment variables for authentication.
    credentials_provider = oss.credentials.EnvironmentVariableCredentialsProvider()

    # Load the default configurations of the SDK and specify the credential provider.
    cfg = oss.config.load_default()
    cfg.credentials_provider = credentials_provider
    # Set the region in the configuration to the one specified in the command line.
    cfg.region = args.region
    # If the endpoint parameter is provided, specify the endpoint.
    if args.endpoint is not None:
        cfg.endpoint = args.endpoint

    # Use the configurations to create an OSSClient instance.
    client = oss.Client(cfg)

    # Create a paginator to allow the ListObjectsV2 operation to list objects.
    paginator = client.list_objects_v2_paginator()

    # Traverse each page of the listed objects.
    for page in paginator.iter_page(oss.ListObjectsV2Request(
            bucket=args.bucket,
            prefix="my-object-", # Set the prefix parameter to my-object-, which means only objects whose names contain the my-object- prefix are listed.
        )
    ):
        # Traverse each object on each page.
        for o in page.contents:
            # Display the name, size, and last modified time of the object.
            print(f'Object: {o.key}, Size: {o.size}, Last_modified: {o.last_modified}')

if __name__ == "__main__":
    main() # Specify the entry points in the main function of the script when the script is directly run.

Listar um número específico de objetos

Para limitar a quantidade de itens retornados, configure o parâmetro MaxKeys. A saída mostrará o nome, o tamanho e a data da última modificação dos objetos listados.

import argparse
import alibabacloud_oss_v2 as oss

# Create a command line parameter parser.
parser = argparse.ArgumentParser(description="list objects v2 sample")
# Specify the --region parameter, which specifies the region in which the bucket is located. This command line parameter is required.
parser.add_argument('--region', help='The region in which the bucket is located.', required=True)
# Specify the --bucket parameter, which specifies the name of the bucket. This command line parameter is required.
parser.add_argument('--bucket', help='The name of the bucket.', required=True)
# Specify the --endpoint parameter, which specifies the endpoint that other services can use to access OSS. This command line parameter is optional.
parser.add_argument('--endpoint', help='The domain names that other services can use to access OSS')

def main():
    args = parser.parse_args()  # Parse the command line parameters.

    # Obtain access credentials from environment variables for authentication.
    credentials_provider = oss.credentials.EnvironmentVariableCredentialsProvider()

    # Load the default configurations of the SDK and specify the credential provider.
    cfg = oss.config.load_default()
    cfg.credentials_provider = credentials_provider
    # Set the region in the configuration to the one specified in the command line.
    cfg.region = args.region
    # If the endpoint parameter is provided, specify the endpoint.
    if args.endpoint is not None:
        cfg.endpoint = args.endpoint

    # Use the configurations to create an OSSClient instance.
    client = oss.Client(cfg)

    # Create a paginator to allow the ListObjectsV2 operation to list objects.
    paginator = client.list_objects_v2_paginator()

    # Traverse each page of the listed objects.
    for page in paginator.iter_page(oss.ListObjectsV2Request(
            bucket=args.bucket,
            max_keys=10, # Specify that up to 10 objects can be returned per page.
        )
    ):
        # Traverse each object on each page.
        for o in page.contents:
            # Display the name, size, and last modified time of the object.
            print(f'Object: {o.key}, Size: {o.size}, Last_modified: {o.last_modified}')

        print('-' * 30)

if __name__ == "__main__":
    main() # Specify the entry points in the main function of the script when the script is directly run.

Listar todos os objetos a partir de uma posição específica

Configure o parâmetro StartAfter para definir a posição inicial da listagem. A operação retornará apenas os objetos cujos nomes sejam alfabeticamente posteriores ao valor especificado.

import argparse
import alibabacloud_oss_v2 as oss

# Create a command line parameter parser.
parser = argparse.ArgumentParser(description="list objects v2 sample")
# Specify the --region parameter, which specifies the region in which the bucket is located. This command line parameter is required.
parser.add_argument('--region', help='The region in which the bucket is located.', required=True)
# Specify the --bucket parameter, which specifies the name of the bucket. This command line parameter is required.
parser.add_argument('--bucket', help='The name of the bucket.', required=True)
# Specify the --endpoint parameter, which specifies the endpoint that other services can use to access OSS. This command line parameter is optional.
parser.add_argument('--endpoint', help='The domain names that other services can use to access OSS')

def main():
    args = parser.parse_args()  # Parse the command line parameters.

    # Obtain access credentials from environment variables for authentication.
    credentials_provider = oss.credentials.EnvironmentVariableCredentialsProvider()

    # Load the default configurations of the SDK and specify the credential provider.
    cfg = oss.config.load_default()
    cfg.credentials_provider = credentials_provider
    # Set the region in the configuration to the one specified in the command line.
    cfg.region = args.region
    # If the endpoint parameter is provided, specify the endpoint.
    if args.endpoint is not None:
        cfg.endpoint = args.endpoint

    # Use the configurations to create an OSSClient instance.
    client = oss.Client(cfg)

    # Create a paginator to allow the ListObjectsV2 operation to list objects.
    paginator = client.list_objects_v2_paginator()

    # Traverse each page of the listed objects.
    for page in paginator.iter_page(oss.ListObjectsV2Request(
            bucket=args.bucket,
            start_after="my-object", # Specify that objects whose names are alphabetically after my-object are listed.
        )
    ):
        # Traverse each object on each page.
        for o in page.contents:
            # Display the name, size, and last modified time of the object.
            print(f'Object: {o.key}, Size: {o.size}, Last_modified: {o.last_modified}')

        print('-' * 30)

if __name__ == "__main__":
    main() # Specify the entry points in the main function of the script when the script is directly run.

Referências

Para acessar o código de exemplo completo de listagem de objetos, visite list_objects_v2.py.