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- Documentation
Torch Object StorageSDK ReferencePythonObject interfaceList objectsList objects (Python SDK)
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List objects (Python SDK)
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This article explains how to use ListObject to list all objects in a specified bucket, files with a specified prefix, files, and subdirectories under a specified directory.
Notes
- The ListObjects interface has been updated to ListObjectsType2. Developers are strongly recommended to use ListObjectsType2. To ensure backward compatibility, TOS continues to support the ListObjects interface.
- To use ListObjects V2, you must have the tos:ListBucket permission. For details, see IAM policy overview.
Parameter description
Parameter | Description |
Parameter | Description |
prefix | Prefix for this query's results. |
delimiter | Character to group object names. |
marker | Specifies where to start listing objects. Lists objects in alphabetical order after this value. Usually the next_marker value returned from the last request. |
max_keys | Returns the maximum number of objects listed, default is 1000. Value range: greater than 0 and less than or equal to 1000 |
Example code
Simple listing
The following code lists 10 objects in the specified bucket.
import os
import tos
# Retrieve AKSK information from environment variables.
ak = os.getenv('TOS_ACCESS_KEY')
sk = os.getenv('TOS_SECRET_KEY')
# Fill in "your endpoint" and "your region" with the corresponding Endpoint of the region where your Bucket is located. Taking the example of North China 2 (Beijing), fill in "your endpoint" with tos-cn-beijing.volces.com and "your region" with cn-beijing.
endpoint = "your endpoint"
region = "your region"
bucket_name = "bucket-test"
try:
# Create a TosClientV2 object to perform operations on buckets and objects
client = tos.TosClientV2(ak, sk, endpoint, region)
# The example code for listing 10 files in a bucket is as follows:
result = client.list_objects(bucket_name, max_keys=10)
for item in result.contents:
print(item.key)
except tos.exceptions.TosClientError as e:
# Operation failed, catch client error, usually caused by invalid request parameters or network issues
print('fail with client error, message:{}, cause: {}'.format(e.message, e.cause))
except tos.exceptions.TosServerError as e:
# Operation failed, catch server error, detailed error information can be obtained from the response
print('fail with server error, code: {}'.format(e.code))
# request id can be used to locate specific issues, it is strongly recommended to save it in the log.
print('error with request id: {}'.format(e.request_id))
print('error with message: {}'.format(e.message))
print('error with http code: {}'.format(e.status_code))
print('error with ec: {}'.format(e.ec))
print('error with request url: {}'.format(e.request_url))
except Exception as e:
print('fail with unknown error: {}'.format(e))
Paginated listing
The following code paginates the listing of objects in bucket bucket-test.
import os
import tos
# Retrieve AKSK information from environment variables.
ak = os.getenv('TOS_ACCESS_KEY')
sk = os.getenv('TOS_SECRET_KEY')
# Fill in "your endpoint" and "your region" with the corresponding Endpoint of the region where your Bucket is located. Taking the example of North China 2 (Beijing), fill in "your endpoint" with tos-cn-beijing.volces.com and "your region" with cn-beijing.
endpoint = "your endpoint"
region = "your region"
bucket_name = "bucket-test"
try:
client = tos.TosClientV2(ak, sk, endpoint, region)
# List the first 1000 objects in the paginated bucket.
result = client.list_objects(bucket_name)
for item in result.contents:
print(item.key)
# List the next 1000 objects in pages.
if result.is_truncated:
result = client.list_objects(bucket_name, marker=result.next_marker)
for item in result.contents:
print(item.key)
except tos.exceptions.TosClientError as e:
# Operation failed, catch client error, usually caused by invalid request parameters or network issues
print('fail with client error, message:{}, cause: {}'.format(e.message, e.cause))
except tos.exceptions.TosServerError as e:
# Operation failed, catch server error, detailed error information can be obtained from the response
print('fail with server error, code: {}'.format(e.code))
# request id can be used to locate specific issues, it is strongly recommended to save it in the log.
print('error with request id: {}'.format(e.request_id))
print('error with message: {}'.format(e.message))
print('error with http code: {}'.format(e.status_code))
print('error with ec: {}'.format(e.ec))
print('error with request url: {}'.format(e.request_url))
except Exception as e:
print('fail with unknown error: {}'.format(e))
List all objects with the specified prefix
The following code lists all objects in bucket bucket-test with the specified prefix.
import os
import tos
# Retrieve AKSK information from environment variables.
ak = os.getenv('TOS_ACCESS_KEY')
sk = os.getenv('TOS_SECRET_KEY')
endpoint = "your endpoint"
region = "your region"
bucket_name = 'bucket-test'
prefix = "your prefix"
try:
# Create a TosClientV2 object to perform operations on buckets and objects
client = tos.TosClientV2(ak, sk, endpoint, region)
is_truncated = True
marker = ""
# List all objects with a specified prefix.
while is_truncated:
result = client.list_objects(bucket_name, prefix=prefix, marker=marker)
for item in result.contents:
print(item.key)
is_truncated = result.is_truncated
marker = result.next_marker
except tos.exceptions.TosClientError as e:
# Operation failed, catch client error, usually caused by invalid request parameters or network issues
print('fail with client error, message:{}, cause: {}'.format(e.message, e.cause))
except tos.exceptions.TosServerError as e:
# Operation failed, catch server error, detailed error information can be obtained from the response
print('fail with server error, code: {}'.format(e.code))
# request id can be used to locate specific issues, it is strongly recommended to save it in the log.
print('error with request id: {}'.format(e.request_id))
print('error with message: {}'.format(e.message))
print('error with http code: {}'.format(e.status_code))
print('error with ec: {}'.format(e.ec))
print('error with request url: {}'.format(e.request_url))
except Exception as e:
print('fail with unknown error: {}'.format(e))
List all objects in a bucket
The following code lists all objects in the specified bucket bucket-test.
import os
import tos
# Retrieve AKSK information from environment variables.
ak = os.getenv('TOS_ACCESS_KEY')
sk = os.getenv('TOS_SECRET_KEY')
endpoint = "your endpoint"
region = "your region"
bucket_name = 'bucket-test'
try:
# Create a TosClientV2 object to perform operations on buckets and objects
client = tos.TosClientV2(ak, sk, endpoint, region)
# List all objects under a specified bucket.
truncated = True
marker = ''
while truncated:
result = client.list_objects(bucket_name, marker=marker)
for item in result.contents:
print(item.key)
truncated = result.is_truncated
marker = result.next_marker
except tos.exceptions.TosClientError as e:
# Operation failed, catch client error, usually caused by invalid request parameters or network issues
print('fail with client error, message:{}, cause: {}'.format(e.message, e.cause))
except tos.exceptions.TosServerError as e:
# Operation failed, catch server error, detailed error information can be obtained from the response
print('fail with server error, code: {}'.format(e.code))
# request id can be used to locate specific issues, it is strongly recommended to save it in the log.
print('error with request id: {}'.format(e.request_id))
print('error with message: {}'.format(e.message))
print('error with http code: {}'.format(e.status_code))
print('error with ec: {}'.format(e.ec))
print('error with request url: {}'.format(e.request_url))
except Exception as e:
print('fail with unknown error: {}'.format(e))
List files and subdirectories under the specified directory
TOS only has the concept of objects; directories can be simulated by creating an object of size 0 that ends with a slash /.
The directory function can be simulated using the parameters delimiter and prefix:
- First, set delimiter to/Set prefix to empty to return objects and subdirectory information in the root directory.
- Then set delimiter to/Set prefix to a subdirectory to return objects and subdirectories within that subdirectory.
The following code lists the objects and subdirectories under the specified directory of bucket bucket-test.
import os
import tos
# Retrieve AKSK information from environment variables.
ak = os.getenv('TOS_ACCESS_KEY')
sk = os.getenv('TOS_SECRET_KEY')
endpoint = "your endpoint"
region = "your region"
bucket_name = 'bucket-test'
try:
# Create a TosClientV2 object to perform operations on buckets and objects
client = tos.TosClientV2(ak, sk, endpoint, region)
# Add subdirectories named fun1, fun2, and fun3 to the Bucket, along with a file named test.
client.put_object(bucket_name, "fun1/")
client.put_object(bucket_name, "fun1/test/")
client.put_object(bucket_name, "fun1/obj.txt")
client.put_object(bucket_name, "fun2/")
client.put_object(bucket_name, "fun3/")
client.put_object(bucket_name, "test")
# List the folders and files in the root directory.
marker = ''
is_truncated = True
while is_truncated:
out = client.list_objects(bucket_name, delimiter="/", marker=marker)
# common_prefixes returns the subdirectories under the root directory.
for prefix in out.common_prefixes:
print('subDir', prefix.prefix)
# The contents return the objects in the root directory.
for content in out.contents:
print('file', content.key)
is_truncated = out.is_truncated
marker = out.next_marker
# List the files and objects under the fun1/ directory.
marker = ''
is_truncated = True
while is_truncated:
out = client.list_objects(bucket_name, delimiter="/", prefix='fun1/', marker=marker)
# common_prefixes returns the subdirectories under the root directory.
for prefix in out.common_prefixes:
print('subDir', prefix.prefix)
# The contents return the objects in the root directory.
for content in out.contents:
print('file', content.key)
is_truncated = out.is_truncated
marker = out.next_marker
except tos.exceptions.TosClientError as e:
# Operation failed, catch client error, usually caused by invalid request parameters or network issues
print('fail with client error, message:{}, cause: {}'.format(e.message, e.cause))
except tos.exceptions.TosServerError as e:
# Operation failed, catch server error, detailed error information can be obtained from the response
print('fail with server error, code: {}'.format(e.code))
# request id can be used to locate specific issues, it is strongly recommended to save it in the log.
print('error with request id: {}'.format(e.request_id))
print('error with message: {}'.format(e.message))
print('error with http code: {}'.format(e.status_code))
print('error with ec: {}'.format(e.ec))
print('error with request url: {}'.format(e.request_url))
except Exception as e:
print('fail with unknown error: {}'.format(e))
Related documentation
Last updated: 2025.09.17 18:22:11
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