Check if an object exists with Python SDK V2 - Object Storage Service

is_object_exist checks whether a named object is present in a bucket and returns a boolean. The call requires the oss:GetObject permission.

Prerequisites

Before you begin, ensure that you have:

The oss:GetObject permission granted to your RAM (Resource Access Management) user. For details, see Attach a custom policy to a RAM user
OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET set as environment variables

Method definition

is_object_exist(bucket: str, key: str, version_id: str | None = None, request_payer: str | None = None, **kwargs) -> bool

Parameters

Parameter	Type	Required	Description
`bucket`	`str`	Yes	The name of the bucket.
`key`	`str`	Yes	The name of the object.
`version_id`	`str \| None`	No	The version ID of the object. Use this when versioning is enabled on the bucket.
`request_payer`	`str \| None`	No	The entity that pays for the request. Set to `requester` for requester-pays buckets.

Return value

Type	Description
`bool`	`True` if the object exists; `False` if it does not.

For the full method reference, see is_object_exist.

Check if an object exists

The following examples use cn-hangzhou as the region. By default, the SDK connects to the public endpoint for that region. To access OSS from another Alibaba Cloud service in the same region, pass the internal endpoint explicitly. For the full list of regions and endpoints, see OSS regions and endpoints.

Basic check

import alibabacloud_oss_v2 as oss

credentials_provider = oss.credentials.EnvironmentVariableCredentialsProvider()
cfg = oss.config.load_default()
cfg.credentials_provider = credentials_provider
cfg.region = "cn-hangzhou"

client = oss.Client(cfg)

result = client.is_object_exist(
    bucket="examplebucket",
    key="exampledir/exampleobject.jpg",
)
print(f"Object exists: {result}")

Check a specific version

If versioning is enabled on the bucket, pass version_id to check a particular version of the object.

result = client.is_object_exist(
    bucket="examplebucket",
    key="exampledir/exampleobject.jpg",
    version_id="<your-version-id>",
)
print(f"Object version exists: {result}")

Full command-line example

The following script accepts the bucket name, object key, and region as command-line arguments.

import argparse
import alibabacloud_oss_v2 as oss

parser = argparse.ArgumentParser(description="Check if an object exists in a specified OSS bucket")
parser.add_argument('--region', help='The region where the bucket is located.', required=True)
parser.add_argument('--bucket', help='The name of the bucket.', required=True)
parser.add_argument('--endpoint', help='The endpoint URL for the OSS service. If not provided, the default endpoint is used.')
parser.add_argument('--key', help='The name of the object.', required=True)

def main():
    args = parser.parse_args()

    credentials_provider = oss.credentials.EnvironmentVariableCredentialsProvider()
    cfg = oss.config.load_default()
    cfg.credentials_provider = credentials_provider
    cfg.region = args.region

    if args.endpoint is not None:
        cfg.endpoint = args.endpoint

    client = oss.Client(cfg)

    result = client.is_object_exist(
        bucket=args.bucket,
        key=args.key,
    )
    print(f"Object exists: {result}")

if __name__ == "__main__":
    main()

Run the script:

python is_object_exist.py \
  --region cn-hangzhou \
  --bucket examplebucket \
  --key exampledir/exampleobject.jpg

References

Complete sample: is_object_exist.py