Object Storage Service:Exception handling

Example of exception handling

The following sample code provides an example on how to handle an exception and display the HTTP status code of the error and the request ID when you attempt to download an object that does not exist:

# -*- coding: utf-8 -*-
import oss2
from oss2.credentials import EnvironmentVariableCredentialsProvider

# Obtain access credentials from the environment variables. Before you run the sample code, make sure that you have configured environment variables OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET. 
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 the bucket.
bucket = oss2.Bucket(auth, endpoint, "examplebucket", region=region)

try:
    # Specify the name of the downloaded object. Example: exampleobject.txt. 
    stream = bucket.get_object('exampleobject.txt')
except oss2.exceptions.NoSuchKey as e:
    print('status={0}, request_id={1}'.format(e.status, e.request_id))            

ClientError

ClientError occurs due to incorrect input on the client. For example, the error occurs when you use the bucket.batch_delete_objects method and receive an empty object list. The value of status for ClientError is oss2.exceptions.OSS_CLIENT_ERROR_STATUS.

RequestError

When the HTTP library throws an error, OSS SDK for Python converts the error to RequestError. The value of status for RequestError is oss2.exceptions.OSS_REQUEST_ERROR_STATUS.

ServerError

When the OSS server returns an HTTP status code, OSS SDK for Python converts the status code to ServerError. ServerError derives multiple subclasses based on the HTTP status code and OSS error code. The NotFound subclass corresponds to HTTP status code 404. The Conflict subclass corresponds to HTTP status code 409.

The following table describes common error codes.