如何捕获 botocore 的 NoSuchKey 异常？

Question

我正在尝试编写“好”的 python 并通过以下方式捕获 S3 no such key 错误：

session = botocore.session.get_session()
client = session.create_client('s3')
try:
    client.get_object(Bucket=BUCKET, Key=FILE)
except NoSuchKey as e:
    print >> sys.stderr, "no such key in bucket"

但 NoSuchKey 未定义，我无法将其跟踪到我需要定义它的导入。

e.__class__ 是 botocore.errorfactory.NoSuchKey 但from botocore.errorfactory import NoSuchKey 给出错误，from botocore.errorfactory import * 也不起作用，我不想捕获一般错误。

Answer 1

from botocore.exceptions import ClientError

try:
    response = self.client.get_object(Bucket=bucket, Key=key)
    return json.loads(response["Body"].read())
except ClientError as ex:
    if ex.response['Error']['Code'] == 'NoSuchKey':
        logger.info('No object found - returning empty')
        return dict()
    else:
        raise

Answer 2

使用 botocore 1.5，看起来客户端句柄暴露了异常类：

session = botocore.session.get_session()
client = session.create_client('s3')
try:
    client.get_object(Bucket=BUCKET, Key=FILE)
except client.exceptions.NoSuchKey as e:
    print >> sys.stderr, "no such key in bucket"

Answer 3

在 boto3 中，我能够访问资源元客户端中的异常。

import boto3

s3 = boto3.resource('s3')
s3_object = s3.Object(bucket_name, key)

try:
    content = s3_object.get()['Body'].read().decode('utf-8')
except s3.meta.client.exceptions.NoSuchKey:
    print("no such key in bucket")

Answer 4

我认为在 Boto3 中最优雅的方式是

session = botocore.session.get_session()
client = session.create_client('s3')

try:
    client.get_object(Bucket=BUCKET, Key=FILE)
except client.exceptions.NoSuchKey:
    print("no such key in bucket")

有关错误处理的文档似乎很少，但以下打印出适用的错误代码：

session = botocore.session.get_session()
client = session.create_client('s3')
try:
    try:
        client.get_object(Bucket=BUCKET, Key=FILE)
    except client.exceptions.InvalidBucketName:
        print("no such key in bucket")
except AttributeError as err:
    print(err)

object 没有属性“InvalidBucketName”。有效的例外是：BucketAlreadyExists、BucketAlreadyOwnedByYou、NoSuchBucket、NoSuchKey、NoSuchUpload、ObjectAlreadyInActiveTierError、ObjectNotInActiveTierError