文档 AWS SDK 示例 GitHub 存储库中还有更多 [S AWS DK 示例](https://github.com/awsdocs/aws-doc-sdk-examples)。
本文属于机器翻译版本。若本译文内容与英语原文存在差异，则一律以英文原文为准。
# 使用 SDK for Python (Boto3) 的 Amazon SQS 示例
以下代码示例向您展示了如何使用 适用于 Python (Boto3) 的 AWS SDK 与 Amazon SQS 配合使用来执行操作和实现常见场景。
*操作*是大型程序的代码摘录，必须在上下文中运行。您可以通过操作了解如何调用单个服务函数，还可以通过函数相关场景的上下文查看操作。
*场景*是向您演示如何通过在一个服务中调用多个函数或与其他 AWS 服务结合来完成特定任务的代码示例。
每个示例都包含一个指向完整源代码的链接，您可以从中找到有关如何在上下文中设置和运行代码的说明。
**Topics**
+ [操作](#actions)
+ [场景](#scenarios)
+ [无服务器示例](#serverless_examples)
## 操作
### `CreateQueue`
以下代码示例演示了如何使用 `CreateQueue`。
**适用于 Python 的 SDK（Boto3）**
还有更多相关信息 GitHub。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/sqs#code-examples)中查找完整示例，了解如何进行设置和运行。
```
def create_queue(name, attributes=None):
"""
Creates an Amazon SQS queue.
:param name: The name of the queue. This is part of the URL assigned to the queue.
:param attributes: The attributes of the queue, such as maximum message size or
whether it's a FIFO queue.
:return: A Queue object that contains metadata about the queue and that can be used
to perform queue operations like sending and receiving messages.
"""
if not attributes:
attributes = {}
try:
queue = sqs.create_queue(QueueName=name, Attributes=attributes)
logger.info("Created queue '%s' with URL=%s", name, queue.url)
except ClientError as error:
logger.exception("Couldn't create queue named '%s'.", name)
raise error
else:
return queue
```
```
class SqsWrapper:
"""Wrapper class for managing Amazon SQS operations."""
def __init__(self, sqs_client: Any) -> None:
"""
Initialize the SqsWrapper.
:param sqs_client: A Boto3 Amazon SQS client.
"""
self.sqs_client = sqs_client
@classmethod
def from_client(cls) -> 'SqsWrapper':
"""
Create an SqsWrapper instance using a default boto3 client.
:return: An instance of this class.
"""
sqs_client = boto3.client('sqs')
return cls(sqs_client)
def create_queue(self, queue_name: str, is_fifo: bool = False) -> str:
"""
Create an SQS queue.
:param queue_name: The name of the queue to create.
:param is_fifo: Whether to create a FIFO queue.
:return: The URL of the created queue.
:raises ClientError: If the queue creation fails.
"""
try:
# Add .fifo suffix for FIFO queues
if is_fifo and not queue_name.endswith('.fifo'):
queue_name += '.fifo'
attributes = {}
if is_fifo:
attributes['FifoQueue'] = 'true'
response = self.sqs_client.create_queue(
QueueName=queue_name,
Attributes=attributes
)
queue_url = response['QueueUrl']
logger.info(f"Created queue: {queue_name} with URL: {queue_url}")
return queue_url
except ClientError as e:
error_code = e.response.get('Error', {}).get('Code', 'Unknown')
logger.error(f"Error creating queue {queue_name}: {error_code} - {e}")
raise
```
+ 有关 API 的详细信息，请参阅适用[CreateQueue](https://docs.aws.amazon.com/goto/boto3/sqs-2012-11-05/CreateQueue)于 *Python 的AWS SDK (Boto3) API 参考*。
### `DeleteMessage`
以下代码示例演示了如何使用 `DeleteMessage`。
**适用于 Python 的 SDK（Boto3）**
还有更多相关信息 GitHub。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/sqs#code-examples)中查找完整示例，了解如何进行设置和运行。
```
def delete_message(message):
"""
Delete a message from a queue. Clients must delete messages after they
are received and processed to remove them from the queue.
:param message: The message to delete. The message's queue URL is contained in
the message's metadata.
:return: None
"""
try:
message.delete()
logger.info("Deleted message: %s", message.message_id)
except ClientError as error:
logger.exception("Couldn't delete message: %s", message.message_id)
raise error
```
+ 有关 API 的详细信息，请参阅适用[DeleteMessage](https://docs.aws.amazon.com/goto/boto3/sqs-2012-11-05/DeleteMessage)于 *Python 的AWS SDK (Boto3) API 参考*。
### `DeleteMessageBatch`
以下代码示例演示了如何使用 `DeleteMessageBatch`。
**适用于 Python 的 SDK（Boto3）**
还有更多相关信息 GitHub。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/sqs#code-examples)中查找完整示例，了解如何进行设置和运行。
```
def delete_messages(queue, messages):
"""
Delete a batch of messages from a queue in a single request.
:param queue: The queue from which to delete the messages.
:param messages: The list of messages to delete.
:return: The response from SQS that contains the list of successful and failed
message deletions.
"""
try:
entries = [
{"Id": str(ind), "ReceiptHandle": msg.receipt_handle}
for ind, msg in enumerate(messages)
]
response = queue.delete_messages(Entries=entries)
if "Successful" in response:
for msg_meta in response["Successful"]:
logger.info("Deleted %s", messages[int(msg_meta["Id"])].receipt_handle)
if "Failed" in response:
for msg_meta in response["Failed"]:
logger.warning(
"Could not delete %s", messages[int(msg_meta["Id"])].receipt_handle
)
except ClientError:
logger.exception("Couldn't delete messages from queue %s", queue)
else:
return response
```
```
class SqsWrapper:
"""Wrapper class for managing Amazon SQS operations."""
def __init__(self, sqs_client: Any) -> None:
"""
Initialize the SqsWrapper.
:param sqs_client: A Boto3 Amazon SQS client.
"""
self.sqs_client = sqs_client
@classmethod
def from_client(cls) -> 'SqsWrapper':
"""
Create an SqsWrapper instance using a default boto3 client.
:return: An instance of this class.
"""
sqs_client = boto3.client('sqs')
return cls(sqs_client)
def delete_messages(self, queue_url: str, messages: List[Dict[str, Any]]) -> bool:
"""
Delete messages from an SQS queue in batches.
:param queue_url: The URL of the queue.
:param messages: List of messages to delete.
:return: True if successful.
:raises ClientError: If deleting messages fails.
"""
try:
if not messages:
return True
# Build delete entries for batch delete
delete_entries = []
for i, message in enumerate(messages):
delete_entries.append({
'Id': str(i),
'ReceiptHandle': message['ReceiptHandle']
})
# Delete messages in batches of 10 (SQS limit)
batch_size = 10
for i in range(0, len(delete_entries), batch_size):
batch = delete_entries[i:i + batch_size]
response = self.sqs_client.delete_message_batch(
QueueUrl=queue_url,
Entries=batch
)
# Check for failures
if 'Failed' in response and response['Failed']:
for failed in response['Failed']:
logger.warning(f"Failed to delete message: {failed}")
logger.info(f"Deleted {len(messages)} messages from {queue_url}")
return True
except ClientError as e:
error_code = e.response.get('Error', {}).get('Code', 'Unknown')
logger.error(f"Error deleting messages: {error_code} - {e}")
raise
```
+ 有关 API 的详细信息，请参阅适用[DeleteMessageBatch](https://docs.aws.amazon.com/goto/boto3/sqs-2012-11-05/DeleteMessageBatch)于 *Python 的AWS SDK (Boto3) API 参考*。
### `DeleteQueue`
以下代码示例演示了如何使用 `DeleteQueue`。
**适用于 Python 的 SDK（Boto3）**
还有更多相关信息 GitHub。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/sqs#code-examples)中查找完整示例，了解如何进行设置和运行。
```
def remove_queue(queue):
"""
Removes an SQS queue. When run against an AWS account, it can take up to
60 seconds before the queue is actually deleted.
:param queue: The queue to delete.
:return: None
"""
try:
queue.delete()
logger.info("Deleted queue with URL=%s.", queue.url)
except ClientError as error:
logger.exception("Couldn't delete queue with URL=%s!", queue.url)
raise error
```
```
class SqsWrapper:
"""Wrapper class for managing Amazon SQS operations."""
def __init__(self, sqs_client: Any) -> None:
"""
Initialize the SqsWrapper.
:param sqs_client: A Boto3 Amazon SQS client.
"""
self.sqs_client = sqs_client
@classmethod
def from_client(cls) -> 'SqsWrapper':
"""
Create an SqsWrapper instance using a default boto3 client.
:return: An instance of this class.
"""
sqs_client = boto3.client('sqs')
return cls(sqs_client)
def delete_queue(self, queue_url: str) -> bool:
"""
Delete an SQS queue.
:param queue_url: The URL of the queue to delete.
:return: True if successful.
:raises ClientError: If the queue deletion fails.
"""
try:
self.sqs_client.delete_queue(QueueUrl=queue_url)
logger.info(f"Deleted queue: {queue_url}")
return True
except ClientError as e:
error_code = e.response.get('Error', {}).get('Code', 'Unknown')
if error_code == 'AWS.SimpleQueueService.NonExistentQueue':
logger.warning(f"Queue not found: {queue_url}")
return True # Already deleted
else:
logger.error(f"Error deleting queue: {error_code} - {e}")
raise
```
+ 有关 API 的详细信息，请参阅适用[DeleteQueue](https://docs.aws.amazon.com/goto/boto3/sqs-2012-11-05/DeleteQueue)于 *Python 的AWS SDK (Boto3) API 参考*。
### `GetQueueAttributes`
以下代码示例演示了如何使用 `GetQueueAttributes`。
**适用于 Python 的 SDK（Boto3）**
还有更多相关信息 GitHub。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/cross_service/topics_and_queues#code-examples)中查找完整示例，了解如何进行设置和运行。
```
class SqsWrapper:
"""Wrapper class for managing Amazon SQS operations."""
def __init__(self, sqs_client: Any) -> None:
"""
Initialize the SqsWrapper.
:param sqs_client: A Boto3 Amazon SQS client.
"""
self.sqs_client = sqs_client
@classmethod
def from_client(cls) -> 'SqsWrapper':
"""
Create an SqsWrapper instance using a default boto3 client.
:return: An instance of this class.
"""
sqs_client = boto3.client('sqs')
return cls(sqs_client)
def get_queue_arn(self, queue_url: str) -> str:
"""
Get the ARN of an SQS queue.
:param queue_url: The URL of the queue.
:return: The ARN of the queue.
:raises ClientError: If getting queue attributes fails.
"""
try:
response = self.sqs_client.get_queue_attributes(
QueueUrl=queue_url,
AttributeNames=['QueueArn']
)
queue_arn = response['Attributes']['QueueArn']
logger.info(f"Queue ARN for {queue_url}: {queue_arn}")
return queue_arn
except ClientError as e:
error_code = e.response.get('Error', {}).get('Code', 'Unknown')
logger.error(f"Error getting queue ARN: {error_code} - {e}")
raise
```
+ 有关 API 的详细信息，请参阅适用[GetQueueAttributes](https://docs.aws.amazon.com/goto/boto3/sqs-2012-11-05/GetQueueAttributes)于 *Python 的AWS SDK (Boto3) API 参考*。
### `GetQueueUrl`
以下代码示例演示了如何使用 `GetQueueUrl`。
**适用于 Python 的 SDK（Boto3）**
还有更多相关信息 GitHub。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/sqs#code-examples)中查找完整示例，了解如何进行设置和运行。
```
def get_queue(name):
"""
Gets an SQS queue by name.
:param name: The name that was used to create the queue.
:return: A Queue object.
"""
try:
queue = sqs.get_queue_by_name(QueueName=name)
logger.info("Got queue '%s' with URL=%s", name, queue.url)
except ClientError as error:
logger.exception("Couldn't get queue named %s.", name)
raise error
else:
return queue
```
+ 有关 API 的详细信息，请参阅适用[GetQueueUrl](https://docs.aws.amazon.com/goto/boto3/sqs-2012-11-05/GetQueueUrl)于 *Python 的AWS SDK (Boto3) API 参考*。
### `ListQueues`
以下代码示例演示了如何使用 `ListQueues`。
**适用于 Python 的 SDK（Boto3）**
还有更多相关信息 GitHub。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/sqs#code-examples)中查找完整示例，了解如何进行设置和运行。
```
def get_queues(prefix=None):
"""
Gets a list of SQS queues. When a prefix is specified, only queues with names
that start with the prefix are returned.
:param prefix: The prefix used to restrict the list of returned queues.
:return: A list of Queue objects.
"""
if prefix:
queue_iter = sqs.queues.filter(QueueNamePrefix=prefix)
else:
queue_iter = sqs.queues.all()
queues = list(queue_iter)
if queues:
logger.info("Got queues: %s", ", ".join([q.url for q in queues]))
else:
logger.warning("No queues found.")
return queues
```
+ 有关 API 的详细信息，请参阅适用[ListQueues](https://docs.aws.amazon.com/goto/boto3/sqs-2012-11-05/ListQueues)于 *Python 的AWS SDK (Boto3) API 参考*。
### `ReceiveMessage`
以下代码示例演示了如何使用 `ReceiveMessage`。
**适用于 Python 的 SDK（Boto3）**
还有更多相关信息 GitHub。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/sqs#code-examples)中查找完整示例，了解如何进行设置和运行。
```
def receive_messages(queue, max_number, wait_time):
"""
Receive a batch of messages in a single request from an SQS queue.
:param queue: The queue from which to receive messages.
:param max_number: The maximum number of messages to receive. The actual number
of messages received might be less.
:param wait_time: The maximum time to wait (in seconds) before returning. When
this number is greater than zero, long polling is used. This
can result in reduced costs and fewer false empty responses.
:return: The list of Message objects received. These each contain the body
of the message and metadata and custom attributes.
"""
try:
messages = queue.receive_messages(
MessageAttributeNames=["All"],
MaxNumberOfMessages=max_number,
WaitTimeSeconds=wait_time,
)
for msg in messages:
logger.info("Received message: %s: %s", msg.message_id, msg.body)
except ClientError as error:
logger.exception("Couldn't receive messages from queue: %s", queue)
raise error
else:
return messages
```
```
class SqsWrapper:
"""Wrapper class for managing Amazon SQS operations."""
def __init__(self, sqs_client: Any) -> None:
"""
Initialize the SqsWrapper.
:param sqs_client: A Boto3 Amazon SQS client.
"""
self.sqs_client = sqs_client
@classmethod
def from_client(cls) -> 'SqsWrapper':
"""
Create an SqsWrapper instance using a default boto3 client.
:return: An instance of this class.
"""
sqs_client = boto3.client('sqs')
return cls(sqs_client)
def receive_messages(self, queue_url: str, max_messages: int = 10) -> List[Dict[str, Any]]:
"""
Receive messages from an SQS queue.
:param queue_url: The URL of the queue to receive messages from.
:param max_messages: Maximum number of messages to receive (1-10).
:return: List of received messages.
:raises ClientError: If receiving messages fails.
"""
try:
# Ensure max_messages is within valid range
max_messages = max(1, min(10, max_messages))
response = self.sqs_client.receive_message(
QueueUrl=queue_url,
MaxNumberOfMessages=max_messages,
WaitTimeSeconds=2, # Short polling
MessageAttributeNames=['All']
)
messages = response.get('Messages', [])
logger.info(f"Received {len(messages)} messages from {queue_url}")
return messages
except ClientError as e:
error_code = e.response.get('Error', {}).get('Code', 'Unknown')
logger.error(f"Error receiving messages: {error_code} - {e}")
raise
```
+ 有关 API 的详细信息，请参阅适用[ReceiveMessage](https://docs.aws.amazon.com/goto/boto3/sqs-2012-11-05/ReceiveMessage)于 *Python 的AWS SDK (Boto3) API 参考*。
### `SendMessage`
以下代码示例演示了如何使用 `SendMessage`。
**适用于 Python 的 SDK（Boto3）**
还有更多相关信息 GitHub。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/sqs#code-examples)中查找完整示例，了解如何进行设置和运行。
```
def send_message(queue, message_body, message_attributes=None):
"""
Send a message to an Amazon SQS queue.
:param queue: The queue that receives the message.
:param message_body: The body text of the message.
:param message_attributes: Custom attributes of the message. These are key-value
pairs that can be whatever you want.
:return: The response from SQS that contains the assigned message ID.
"""
if not message_attributes:
message_attributes = {}
try:
response = queue.send_message(
MessageBody=message_body, MessageAttributes=message_attributes
)
except ClientError as error:
logger.exception("Send message failed: %s", message_body)
raise error
else:
return response
```
+ 有关 API 的详细信息，请参阅适用[SendMessage](https://docs.aws.amazon.com/goto/boto3/sqs-2012-11-05/SendMessage)于 *Python 的AWS SDK (Boto3) API 参考*。
### `SendMessageBatch`
以下代码示例演示了如何使用 `SendMessageBatch`。
**适用于 Python 的 SDK（Boto3）**
还有更多相关信息 GitHub。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/sqs#code-examples)中查找完整示例，了解如何进行设置和运行。
```
def send_messages(queue, messages):
"""
Send a batch of messages in a single request to an SQS queue.
This request may return overall success even when some messages were not sent.
The caller must inspect the Successful and Failed lists in the response and
resend any failed messages.
:param queue: The queue to receive the messages.
:param messages: The messages to send to the queue. These are simplified to
contain only the message body and attributes.
:return: The response from SQS that contains the list of successful and failed
messages.
"""
try:
entries = [
{
"Id": str(ind),
"MessageBody": msg["body"],
"MessageAttributes": msg["attributes"],
}
for ind, msg in enumerate(messages)
]
response = queue.send_messages(Entries=entries)
if "Successful" in response:
for msg_meta in response["Successful"]:
logger.info(
"Message sent: %s: %s",
msg_meta["MessageId"],
messages[int(msg_meta["Id"])]["body"],
)
if "Failed" in response:
for msg_meta in response["Failed"]:
logger.warning(
"Failed to send: %s: %s",
msg_meta["MessageId"],
messages[int(msg_meta["Id"])]["body"],
)
except ClientError as error:
logger.exception("Send messages failed to queue: %s", queue)
raise error
else:
return response
```
+ 有关 API 的详细信息，请参阅适用[SendMessageBatch](https://docs.aws.amazon.com/goto/boto3/sqs-2012-11-05/SendMessageBatch)于 *Python 的AWS SDK (Boto3) API 参考*。
### `SetQueueAttributes`
以下代码示例演示了如何使用 `SetQueueAttributes`。
**适用于 Python 的 SDK（Boto3）**
还有更多相关信息 GitHub。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/cross_service/topics_and_queues#code-examples)中查找完整示例，了解如何进行设置和运行。
为主题设置队列的策略属性。
```
class SqsWrapper:
"""Wrapper class for managing Amazon SQS operations."""
def __init__(self, sqs_client: Any) -> None:
"""
Initialize the SqsWrapper.
:param sqs_client: A Boto3 Amazon SQS client.
"""
self.sqs_client = sqs_client
@classmethod
def from_client(cls) -> 'SqsWrapper':
"""
Create an SqsWrapper instance using a default boto3 client.
:return: An instance of this class.
"""
sqs_client = boto3.client('sqs')
return cls(sqs_client)
def set_queue_policy_for_topic(self, queue_arn: str, topic_arn: str, queue_url: str) -> bool:
"""
Set the queue policy to allow SNS to send messages to the queue.
:param queue_arn: The ARN of the SQS queue.
:param topic_arn: The ARN of the SNS topic.
:param queue_url: The URL of the SQS queue.
:return: True if successful.
:raises ClientError: If setting the queue policy fails.
"""
try:
# Create policy that allows SNS to send messages to the queue
policy = {
"Version":"2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Principal": {
"Service": "sns.amazonaws.com"
},
"Action": "sqs:SendMessage",
"Resource": queue_arn,
"Condition": {
"ArnEquals": {
"aws:SourceArn": topic_arn
}
}
}
]
}
self.sqs_client.set_queue_attributes(
QueueUrl=queue_url,
Attributes={
'Policy': json.dumps(policy)
}
)
logger.info(f"Set queue policy for {queue_url} to allow messages from {topic_arn}")
return True
except ClientError as e:
error_code = e.response.get('Error', {}).get('Code', 'Unknown')
logger.error(f"Error setting queue policy: {error_code} - {e}")
raise
```
+ 有关 API 的详细信息，请参阅适用[SetQueueAttributes](https://docs.aws.amazon.com/goto/boto3/sqs-2012-11-05/SetQueueAttributes)于 *Python 的AWS SDK (Boto3) API 参考*。
## 场景
### 创建 Messenger 应用程序
以下代码示例说明如何创建用于从数据库表中检索消息记录的 AWS Step Functions Messenger 应用程序。
**适用于 Python 的 SDK（Boto3）**
演示如何使用 with 创建信使应用程序，该应用程序从亚马逊 DynamoDB 表中检索消息记录并 适用于 Python (Boto3) 的 AWS SDK 通过 AWS Step Functions 亚马逊简单队列服务 (Amazon SQS) Simple SQUEE Service 将其发送。状态机集成了扫描数据库中是否有未发送消息的 AWS Lambda 功能。
+ 创建检索并更新 Amazon DynamoDB 表中的消息记录的状态机。
+ 更新状态机定义以便也将消息发送到 Amazon Simple Queue Service (Amazon SQS)。
+ 启动和停止状态机运行。
+ 使用服务集成从状态机连接到 Lambda、DynamoDB 和 Amazon SQS。
有关如何设置和运行的完整源代码和说明，请参阅上的完整示例[GitHub](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/cross_service/stepfunctions_messenger)。
**本示例中使用的服务**
+ DynamoDB
+ Lambda
+ Amazon SQS
+ Step Functions
### 创建 Amazon Textract 浏览器应用程序
以下代码示例演示如何通过交互式应用程序探索 Amazon Textract 输出。
**适用于 Python 的 SDK（Boto3）**
演示如何 适用于 Python (Boto3) 的 AWS SDK 与 Amazon Textract 配合使用来检测文档图像中的文本、表单和表格元素。输入图像和 Amazon Textract 输出在 Tkinter 应用程序中显示，该应用程序可让您探索检测到的元素。
+ 将文档图像提交到 Amazon Textract 并探索检测到的元素的输出。
+ 将图像直接提交到 Amazon Textract，或通过 Amazon Simple Storage Service（Amazon S3）桶提交图像。
+ 使用异步 APIs 启动任务，该任务在任务完成时向亚马逊简单通知服务 (Amazon SNS) Simple Notification Service 主题发布通知。
+ 轮询 Amazon Simple Queue Service (Amazon SQS) 队列，以获取任务完成消息并显示结果。
有关如何设置和运行的完整源代码和说明，请参阅上的完整示例[GitHub](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/cross_service/textract_explorer)。
**本示例中使用的服务**
+ Amazon Cognito Identity
+ Amazon S3
+ Amazon SNS
+ Amazon SQS
+ Amazon Textract
### 创建并发布到 FIFO 主题
以下代码示例显示了如何创建并发布到 Amazon SNS FIFO 主题。
**适用于 Python 的 SDK（Boto3）**
还有更多相关信息 GitHub。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/sns#code-examples)中查找完整示例，了解如何进行设置和运行。
创建 Amazon SNS FIFO 主题，将 Amazon SQS FIFO 队列和标准队列订阅到主题，并发布一条消息到主题。
```
def usage_demo():
"""Shows how to subscribe queues to a FIFO topic."""
print("-" * 88)
print("Welcome to the `Subscribe queues to a FIFO topic` demo!")
print("-" * 88)
sns = boto3.resource("sns")
sqs = boto3.resource("sqs")
fifo_topic_wrapper = FifoTopicWrapper(sns)
sns_wrapper = SnsWrapper(sns)
prefix = "sqs-subscribe-demo-"
queues = set()
subscriptions = set()
wholesale_queue = sqs.create_queue(
QueueName=prefix + "wholesale.fifo",
Attributes={
"MaximumMessageSize": str(4096),
"ReceiveMessageWaitTimeSeconds": str(10),
"VisibilityTimeout": str(300),
"FifoQueue": str(True),
"ContentBasedDeduplication": str(True),
},
)
queues.add(wholesale_queue)
print(f"Created FIFO queue with URL: {wholesale_queue.url}.")
retail_queue = sqs.create_queue(
QueueName=prefix + "retail.fifo",
Attributes={
"MaximumMessageSize": str(4096),
"ReceiveMessageWaitTimeSeconds": str(10),
"VisibilityTimeout": str(300),
"FifoQueue": str(True),
"ContentBasedDeduplication": str(True),
},
)
queues.add(retail_queue)
print(f"Created FIFO queue with URL: {retail_queue.url}.")
analytics_queue = sqs.create_queue(QueueName=prefix + "analytics", Attributes={})
queues.add(analytics_queue)
print(f"Created standard queue with URL: {analytics_queue.url}.")
topic = fifo_topic_wrapper.create_fifo_topic("price-updates-topic.fifo")
print(f"Created FIFO topic: {topic.attributes['TopicArn']}.")
for q in queues:
fifo_topic_wrapper.add_access_policy(q, topic.attributes["TopicArn"])
print(f"Added access policies for topic: {topic.attributes['TopicArn']}.")
for q in queues:
sub = fifo_topic_wrapper.subscribe_queue_to_topic(
topic, q.attributes["QueueArn"]
)
subscriptions.add(sub)
print(f"Subscribed queues to topic: {topic.attributes['TopicArn']}.")
input("Press Enter to publish a message to the topic.")
message_id = fifo_topic_wrapper.publish_price_update(
topic, '{"product": 214, "price": 79.99}', "Consumables"
)
print(f"Published price update with message ID: {message_id}.")
# Clean up the subscriptions, queues, and topic.
input("Press Enter to clean up resources.")
for s in subscriptions:
sns_wrapper.delete_subscription(s)
sns_wrapper.delete_topic(topic)
for q in queues:
fifo_topic_wrapper.delete_queue(q)
print(f"Deleted subscriptions, queues, and topic.")
print("Thanks for watching!")
print("-" * 88)
class FifoTopicWrapper:
"""Encapsulates Amazon SNS FIFO topic and subscription functions."""
def __init__(self, sns_resource):
"""
:param sns_resource: A Boto3 Amazon SNS resource.
"""
self.sns_resource = sns_resource
def create_fifo_topic(self, topic_name):
"""
Create a FIFO topic.
Topic names must be made up of only uppercase and lowercase ASCII letters,
numbers, underscores, and hyphens, and must be between 1 and 256 characters long.
For a FIFO topic, the name must end with the .fifo suffix.
:param topic_name: The name for the topic.
:return: The new topic.
"""
try:
topic = self.sns_resource.create_topic(
Name=topic_name,
Attributes={
"FifoTopic": str(True),
"ContentBasedDeduplication": str(False),
"FifoThroughputScope": "MessageGroup",
},
)
logger.info("Created FIFO topic with name=%s.", topic_name)
return topic
except ClientError as error:
logger.exception("Couldn't create topic with name=%s!", topic_name)
raise error
@staticmethod
def add_access_policy(queue, topic_arn):
"""
Add the necessary access policy to a queue, so
it can receive messages from a topic.
:param queue: The queue resource.
:param topic_arn: The ARN of the topic.
:return: None.
"""
try:
queue.set_attributes(
Attributes={
"Policy": json.dumps(
{
"Version":"2012-10-17",
"Statement": [
{
"Sid": "test-sid",
"Effect": "Allow",
"Principal": {"AWS": "*"},
"Action": "SQS:SendMessage",
"Resource": queue.attributes["QueueArn"],
"Condition": {
"ArnLike": {"aws:SourceArn": topic_arn}
},
}
],
}
)
}
)
logger.info("Added trust policy to the queue.")
except ClientError as error:
logger.exception("Couldn't add trust policy to the queue!")
raise error
@staticmethod
def subscribe_queue_to_topic(topic, queue_arn):
"""
Subscribe a queue to a topic.
:param topic: The topic resource.
:param queue_arn: The ARN of the queue.
:return: The subscription resource.
"""
try:
subscription = topic.subscribe(
Protocol="sqs",
Endpoint=queue_arn,
)
logger.info("The queue is subscribed to the topic.")
return subscription
except ClientError as error:
logger.exception("Couldn't subscribe queue to topic!")
raise error
@staticmethod
def publish_price_update(topic, payload, group_id):
"""
Compose and publish a message that updates the wholesale price.
:param topic: The topic to publish to.
:param payload: The message to publish.
:param group_id: The group ID for the message.
:return: The ID of the message.
"""
try:
att_dict = {"business": {"DataType": "String", "StringValue": "wholesale"}}
dedup_id = uuid.uuid4()
response = topic.publish(
Subject="Price Update",
Message=payload,
MessageAttributes=att_dict,
MessageGroupId=group_id,
MessageDeduplicationId=str(dedup_id),
)
message_id = response["MessageId"]
logger.info("Published message to topic %s.", topic.arn)
except ClientError as error:
logger.exception("Couldn't publish message to topic %s.", topic.arn)
raise error
return message_id
@staticmethod
def delete_queue(queue):
"""
Removes an SQS queue. When run against an AWS account, it can take up to
60 seconds before the queue is actually deleted.
:param queue: The queue to delete.
:return: None
"""
try:
queue.delete()
logger.info("Deleted queue with URL=%s.", queue.url)
except ClientError as error:
logger.exception("Couldn't delete queue with URL=%s!", queue.url)
raise error
```
+ 有关 API 详细信息，请参阅《AWS SDK for Python (Boto3) API Reference》**中的以下主题。
+ [CreateTopic](https://docs.aws.amazon.com/goto/boto3/sns-2010-03-31/CreateTopic)
+ [发布](https://docs.aws.amazon.com/goto/boto3/sns-2010-03-31/Publish)
+ [Subscribe](https://docs.aws.amazon.com/goto/boto3/sns-2010-03-31/Subscribe)
### 检测视频中的人物和对象
以下代码示例演示如何使用 Amazon Rekognition 检测视频中的人物和物体。
**适用于 Python 的 SDK（Boto3）**
通过启动异步检测任务，使用 Amazon Rekognition 来检测视频中的人脸、对象和人物。此示例还将 Amazon Rekognition 配置为在任务完成时通知 Amazon Simple Notification Service (Amazon SNS) 主题，并订阅该主题的 Amazon Simple Queue Service (Amazon SQS) 队列。当队列收到有关任务的消息时，将检索该任务并输出结果。
最好在上查看此示例 GitHub。有关如何设置和运行的完整源代码和说明，请参阅上的完整示例[GitHub](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/rekognition)。
**本示例中使用的服务**
+ Amazon Rekognition
+ Amazon S3
+ Amazon SES
+ Amazon SNS
+ Amazon SQS
### 将消息发布到队列
以下代码示例演示了操作流程：
+ 创建主题（FIFO 或非 FIFO）。
+ 针对主题订阅多个队列，并提供应用筛选条件的选项。
+ 将消息发布到主题。
+ 轮询队列中是否有收到的消息。
**适用于 Python 的 SDK（Boto3）**
还有更多相关信息 GitHub。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/cross_service/topics_and_queues#code-examples)中查找完整示例，了解如何进行设置和运行。
在命令提示符中运行交互式场景。
```
class TopicsAndQueuesScenario:
"""Manages the Topics and Queues feature scenario."""
DASHES = "-" * 80
def __init__(self, sns_wrapper: SnsWrapper, sqs_wrapper: SqsWrapper) -> None:
"""
Initialize the Topics and Queues scenario.
:param sns_wrapper: SnsWrapper instance for SNS operations.
:param sqs_wrapper: SqsWrapper instance for SQS operations.
"""
self.sns_wrapper = sns_wrapper
self.sqs_wrapper = sqs_wrapper
# Scenario state
self.use_fifo_topic = False
self.use_content_based_deduplication = False
self.topic_name = None
self.topic_arn = None
self.queue_count = 2
self.queue_urls = []
self.subscription_arns = []
self.tones = ["cheerful", "funny", "serious", "sincere"]
def run_scenario(self) -> None:
"""Run the Topics and Queues feature scenario."""
print(self.DASHES)
print("Welcome to messaging with topics and queues.")
print(self.DASHES)
print(f"""
In this scenario, you will create an SNS topic and subscribe {self.queue_count} SQS queues to the topic.
You can select from several options for configuring the topic and the subscriptions for the queues.
You can then post to the topic and see the results in the queues.
""")
try:
# Setup Phase
print(self.DASHES)
self._setup_topic()
print(self.DASHES)
self._setup_queues()
print(self.DASHES)
# Demonstration Phase
self._publish_messages()
print(self.DASHES)
# Examination Phase
self._poll_queues_for_messages()
print(self.DASHES)
# Cleanup Phase
self._cleanup_resources()
print(self.DASHES)
except Exception as e:
logger.error(f"Scenario failed: {e}")
print(f"There was a problem with the scenario: {e}")
print("\nInitiating cleanup...")
try:
self._cleanup_resources()
except Exception as cleanup_error:
logger.error(f"Error during cleanup: {cleanup_error}")
print("Messaging with topics and queues scenario is complete.")
print(self.DASHES)
def _setup_topic(self) -> None:
"""Set up the SNS topic to be used with the queues."""
print("SNS topics can be configured as FIFO (First-In-First-Out).")
print("FIFO topics deliver messages in order and support deduplication and message filtering.")
print()
self.use_fifo_topic = q.ask("Would you like to work with FIFO topics? (y/n): ", q.is_yesno)
if self.use_fifo_topic:
print(self.DASHES)
self.topic_name = q.ask("Enter a name for your SNS topic: ", q.non_empty)
print("Because you have selected a FIFO topic, '.fifo' must be appended to the topic name.")
print()
print(self.DASHES)
print("""
Because you have chosen a FIFO topic, deduplication is supported.
Deduplication IDs are either set in the message or automatically generated
from content using a hash function.
If a message is successfully published to an SNS FIFO topic, any message
published and determined to have the same deduplication ID,
within the five-minute deduplication interval, is accepted but not delivered.
For more information about deduplication,
see https://docs.aws.amazon.com/sns/latest/dg/fifo-message-dedup.html.
""")
self.use_content_based_deduplication = q.ask(
"Use content-based deduplication instead of entering a deduplication ID? (y/n): ",
q.is_yesno
)
else:
self.topic_name = q.ask("Enter a name for your SNS topic: ", q.non_empty)
print(self.DASHES)
# Create the topic
self.topic_arn = self.sns_wrapper.create_topic(
self.topic_name,
self.use_fifo_topic,
self.use_content_based_deduplication
)
print(f"Your new topic with the name {self.topic_name}")
print(f" and Amazon Resource Name (ARN) {self.topic_arn}")
print(f" has been created.")
print()
def _setup_queues(self) -> None:
"""Set up the SQS queues and subscribe them to the topic."""
print(f"Now you will create {self.queue_count} Amazon Simple Queue Service (Amazon SQS) queues to subscribe to the topic.")
for i in range(self.queue_count):
queue_name = q.ask(f"Enter a name for SQS queue #{i+1}: ", q.non_empty)
if self.use_fifo_topic and i == 0:
print("Because you have selected a FIFO topic, '.fifo' must be appended to the queue name.")
# Create the queue
queue_url = self.sqs_wrapper.create_queue(queue_name, self.use_fifo_topic)
self.queue_urls.append(queue_url)
print(f"Your new queue with the name {queue_name}")
print(f" and queue URL {queue_url}")
print(f" has been created.")
print()
if i == 0:
print("The queue URL is used to retrieve the queue ARN,")
print("which is used to create a subscription.")
print(self.DASHES)
# Get queue ARN
queue_arn = self.sqs_wrapper.get_queue_arn(queue_url)
if i == 0:
print("An AWS Identity and Access Management (IAM) policy must be attached to an SQS queue,")
print("enabling it to receive messages from an SNS topic.")
# Set queue policy to allow SNS to send messages
self.sqs_wrapper.set_queue_policy_for_topic(queue_arn, self.topic_arn, queue_url)
# Set up message filtering if using FIFO
subscription_arn = self._setup_subscription_with_filter(i, queue_arn, queue_name)
self.subscription_arns.append(subscription_arn)
def _setup_subscription_with_filter(self, queue_index: int, queue_arn: str, queue_name: str) -> str:
"""Set up subscription with optional message filtering."""
filter_policy = None
if self.use_fifo_topic:
print(self.DASHES)
if queue_index == 0:
print("Subscriptions to a FIFO topic can have filters.")
print("If you add a filter to this subscription, then only the filtered messages")
print("will be received in the queue.")
print()
print("For information about message filtering,")
print("see https://docs.aws.amazon.com/sns/latest/dg/sns-message-filtering.html")
print()
print("For this example, you can filter messages by a TONE attribute.")
use_filter = q.ask(f"Filter messages for {queue_name}'s subscription to the topic? (y/n): ", q.is_yesno)
if use_filter:
filter_policy = self._create_filter_policy()
subscription_arn = self.sns_wrapper.subscribe_queue_to_topic(
self.topic_arn, queue_arn, filter_policy
)
print(f"The queue {queue_name} has been subscribed to the topic {self.topic_name}")
print(f" with the subscription ARN {subscription_arn}")
return subscription_arn
def _create_filter_policy(self) -> str:
"""Create a message filter policy based on user selections."""
print(self.DASHES)
print("You can filter messages by one or more of the following TONE attributes.")
filter_selections = []
selection_number = 0
while True:
print("Enter a number to add a TONE filter, or enter 0 to stop adding filters.")
for i, tone in enumerate(self.tones, 1):
print(f" {i}. {tone}")
selection = q.ask("Your choice: ", q.is_int, q.in_range(0, len(self.tones)))
if selection == 0:
break
elif selection > 0 and self.tones[selection - 1] not in filter_selections:
filter_selections.append(self.tones[selection - 1])
print(f"Added '{self.tones[selection - 1]}' to filter list.")
if filter_selections:
filters = {"tone": filter_selections}
return json.dumps(filters)
return None
def _publish_messages(self) -> None:
"""Publish messages to the topic with various options."""
print("Now we can publish messages.")
keep_sending = True
while keep_sending:
print()
message = q.ask("Enter a message to publish: ", q.non_empty)
message_group_id = None
deduplication_id = None
tone_attribute = None
if self.use_fifo_topic:
print("Because you are using a FIFO topic, you must set a message group ID.")
print("All messages within the same group will be received in the order they were published.")
print()
message_group_id = q.ask("Enter a message group ID for this message: ", q.non_empty)
if not self.use_content_based_deduplication:
print("Because you are not using content-based deduplication,")
print("you must enter a deduplication ID.")
deduplication_id = q.ask("Enter a deduplication ID for this message: ", q.non_empty)
# Ask about tone attribute
add_attribute = q.ask("Add an attribute to this message? (y/n): ", q.is_yesno)
if add_attribute:
print("Enter a number for an attribute:")
for i, tone in enumerate(self.tones, 1):
print(f" {i}. {tone}")
selection = q.ask("Your choice: ", q.is_int, q.in_range(1, len(self.tones)))
if 1 <= selection <= len(self.tones):
tone_attribute = self.tones[selection - 1]
# Publish the message
message_id = self.sns_wrapper.publish_message(
self.topic_arn,
message,
tone_attribute,
deduplication_id,
message_group_id
)
print(f"Message published with ID: {message_id}")
keep_sending = q.ask("Send another message? (y/n): ", q.is_yesno)
def _poll_queues_for_messages(self) -> None:
"""Poll all queues for messages and display results."""
for i, queue_url in enumerate(self.queue_urls):
print(f"Polling queue #{i+1} at {queue_url} for messages...")
q.ask("Press Enter to continue...")
messages = self._poll_queue_for_messages(queue_url)
if messages:
print(f"{len(messages)} message(s) were received by queue #{i+1}")
for j, message in enumerate(messages, 1):
print(f" Message {j}:")
# Parse the SNS message body to get the actual message
try:
sns_message = json.loads(message['Body'])
actual_message = sns_message.get('Message', message['Body'])
print(f" {actual_message}")
except (json.JSONDecodeError, KeyError):
print(f" {message['Body']}")
# Delete the messages
self.sqs_wrapper.delete_messages(queue_url, messages)
print(f"Messages deleted from queue #{i+1}")
else:
print(f"No messages received by queue #{i+1}")
print(self.DASHES)
def _poll_queue_for_messages(self, queue_url: str) -> List[Dict[str, Any]]:
"""Poll a single queue for messages."""
all_messages = []
max_polls = 3 # Limit polling to avoid infinite loops
for poll_count in range(max_polls):
messages = self.sqs_wrapper.receive_messages(queue_url, 10)
if messages:
all_messages.extend(messages)
print(f" Received {len(messages)} messages in poll {poll_count + 1}")
# Small delay between polls
time.sleep(1)
else:
print(f" No messages in poll {poll_count + 1}")
break
return all_messages
def _cleanup_resources(self) -> None:
"""Clean up all resources created during the scenario."""
print("Cleaning up resources...")
# Delete queues
for i, queue_url in enumerate(self.queue_urls):
if queue_url:
delete_queue = q.ask(f"Delete queue #{i+1} with URL {queue_url}? (y/n): ", q.is_yesno)
if delete_queue:
try:
self.sqs_wrapper.delete_queue(queue_url)
print(f"Deleted queue #{i+1}")
except Exception as e:
print(f"Error deleting queue #{i+1}: {e}")
# Unsubscribe from topic
for i, subscription_arn in enumerate(self.subscription_arns):
if subscription_arn:
try:
self.sns_wrapper.unsubscribe(subscription_arn)
print(f"Unsubscribed subscription #{i+1}")
except Exception as e:
print(f"Error unsubscribing #{i+1}: {e}")
# Delete topic
if self.topic_arn:
delete_topic = q.ask(f"Delete topic {self.topic_name}? (y/n): ", q.is_yesno)
if delete_topic:
try:
self.sns_wrapper.delete_topic(self.topic_arn)
print(f"Deleted topic {self.topic_name}")
except Exception as e:
print(f"Error deleting topic: {e}")
print("Resource cleanup complete.")
```
创建包含 Amazon SNS 和 Amazon SQS 操作的类，以便在场景中使用。
```
class SnsWrapper:
"""Wrapper class for managing Amazon SNS operations."""
def __init__(self, sns_client: Any) -> None:
"""
Initialize the SnsWrapper.
:param sns_client: A Boto3 Amazon SNS client.
"""
self.sns_client = sns_client
@classmethod
def from_client(cls) -> 'SnsWrapper':
"""
Create an SnsWrapper instance using a default boto3 client.
:return: An instance of this class.
"""
sns_client = boto3.client('sns')
return cls(sns_client)
def create_topic(
self,
topic_name: str,
is_fifo: bool = False,
content_based_deduplication: bool = False
) -> str:
"""
Create an SNS topic.
:param topic_name: The name of the topic to create.
:param is_fifo: Whether to create a FIFO topic.
:param content_based_deduplication: Whether to use content-based deduplication for FIFO topics.
:return: The ARN of the created topic.
:raises ClientError: If the topic creation fails.
"""
try:
# Add .fifo suffix for FIFO topics
if is_fifo and not topic_name.endswith('.fifo'):
topic_name += '.fifo'
attributes = {}
if is_fifo:
attributes['FifoTopic'] = 'true'
if content_based_deduplication:
attributes['ContentBasedDeduplication'] = 'true'
response = self.sns_client.create_topic(
Name=topic_name,
Attributes=attributes
)
topic_arn = response['TopicArn']
logger.info(f"Created topic: {topic_name} with ARN: {topic_arn}")
return topic_arn
except ClientError as e:
error_code = e.response.get('Error', {}).get('Code', 'Unknown')
logger.error(f"Error creating topic {topic_name}: {error_code} - {e}")
raise
def subscribe_queue_to_topic(
self,
topic_arn: str,
queue_arn: str,
filter_policy: Optional[str] = None
) -> str:
"""
Subscribe an SQS queue to an SNS topic.
:param topic_arn: The ARN of the SNS topic.
:param queue_arn: The ARN of the SQS queue.
:param filter_policy: Optional JSON filter policy for message filtering.
:return: The ARN of the subscription.
:raises ClientError: If the subscription fails.
"""
try:
attributes = {}
if filter_policy:
attributes['FilterPolicy'] = filter_policy
response = self.sns_client.subscribe(
TopicArn=topic_arn,
Protocol='sqs',
Endpoint=queue_arn,
Attributes=attributes
)
subscription_arn = response['SubscriptionArn']
logger.info(f"Subscribed queue {queue_arn} to topic {topic_arn}")
return subscription_arn
except ClientError as e:
error_code = e.response.get('Error', {}).get('Code', 'Unknown')
logger.error(f"Error subscribing queue to topic: {error_code} - {e}")
raise
def publish_message(
self,
topic_arn: str,
message: str,
tone_attribute: Optional[str] = None,
deduplication_id: Optional[str] = None,
message_group_id: Optional[str] = None
) -> str:
"""
Publish a message to an SNS topic.
:param topic_arn: The ARN of the SNS topic.
:param message: The message content to publish.
:param tone_attribute: Optional tone attribute for message filtering.
:param deduplication_id: Optional deduplication ID for FIFO topics.
:param message_group_id: Optional message group ID for FIFO topics.
:return: The message ID of the published message.
:raises ClientError: If the message publication fails.
"""
try:
publish_args = {
'TopicArn': topic_arn,
'Message': message
}
# Add message attributes if tone is specified
if tone_attribute:
publish_args['MessageAttributes'] = {
'tone': {
'DataType': 'String',
'StringValue': tone_attribute
}
}
# Add FIFO-specific parameters
if message_group_id:
publish_args['MessageGroupId'] = message_group_id
if deduplication_id:
publish_args['MessageDeduplicationId'] = deduplication_id
response = self.sns_client.publish(**publish_args)
message_id = response['MessageId']
logger.info(f"Published message to topic {topic_arn} with ID: {message_id}")
return message_id
except ClientError as e:
error_code = e.response.get('Error', {}).get('Code', 'Unknown')
logger.error(f"Error publishing message to topic: {error_code} - {e}")
raise
def unsubscribe(self, subscription_arn: str) -> bool:
"""
Unsubscribe from an SNS topic.
:param subscription_arn: The ARN of the subscription to remove.
:return: True if successful.
:raises ClientError: If the unsubscribe operation fails.
"""
try:
self.sns_client.unsubscribe(SubscriptionArn=subscription_arn)
logger.info(f"Unsubscribed: {subscription_arn}")
return True
except ClientError as e:
error_code = e.response.get('Error', {}).get('Code', 'Unknown')
if error_code == 'NotFound':
logger.warning(f"Subscription not found: {subscription_arn}")
return True # Already unsubscribed
else:
logger.error(f"Error unsubscribing: {error_code} - {e}")
raise
def delete_topic(self, topic_arn: str) -> bool:
"""
Delete an SNS topic.
:param topic_arn: The ARN of the topic to delete.
:return: True if successful.
:raises ClientError: If the topic deletion fails.
"""
try:
self.sns_client.delete_topic(TopicArn=topic_arn)
logger.info(f"Deleted topic: {topic_arn}")
return True
except ClientError as e:
error_code = e.response.get('Error', {}).get('Code', 'Unknown')
if error_code == 'NotFound':
logger.warning(f"Topic not found: {topic_arn}")
return True # Already deleted
else:
logger.error(f"Error deleting topic: {error_code} - {e}")
raise
def list_topics(self) -> list:
"""
List all SNS topics in the account using pagination.
:return: List of topic ARNs.
:raises ClientError: If listing topics fails.
"""
try:
topics = []
paginator = self.sns_client.get_paginator('list_topics')
for page in paginator.paginate():
topics.extend([topic['TopicArn'] for topic in page.get('Topics', [])])
logger.info(f"Found {len(topics)} topics")
return topics
except ClientError as e:
error_code = e.response.get('Error', {}).get('Code', 'Unknown')
if error_code == 'AuthorizationError':
logger.error("Authorization error listing topics - check IAM permissions")
else:
logger.error(f"Error listing topics: {error_code} - {e}")
raise
class SqsWrapper:
"""Wrapper class for managing Amazon SQS operations."""
def __init__(self, sqs_client: Any) -> None:
"""
Initialize the SqsWrapper.
:param sqs_client: A Boto3 Amazon SQS client.
"""
self.sqs_client = sqs_client
@classmethod
def from_client(cls) -> 'SqsWrapper':
"""
Create an SqsWrapper instance using a default boto3 client.
:return: An instance of this class.
"""
sqs_client = boto3.client('sqs')
return cls(sqs_client)
def create_queue(self, queue_name: str, is_fifo: bool = False) -> str:
"""
Create an SQS queue.
:param queue_name: The name of the queue to create.
:param is_fifo: Whether to create a FIFO queue.
:return: The URL of the created queue.
:raises ClientError: If the queue creation fails.
"""
try:
# Add .fifo suffix for FIFO queues
if is_fifo and not queue_name.endswith('.fifo'):
queue_name += '.fifo'
attributes = {}
if is_fifo:
attributes['FifoQueue'] = 'true'
response = self.sqs_client.create_queue(
QueueName=queue_name,
Attributes=attributes
)
queue_url = response['QueueUrl']
logger.info(f"Created queue: {queue_name} with URL: {queue_url}")
return queue_url
except ClientError as e:
error_code = e.response.get('Error', {}).get('Code', 'Unknown')
logger.error(f"Error creating queue {queue_name}: {error_code} - {e}")
raise
def get_queue_arn(self, queue_url: str) -> str:
"""
Get the ARN of an SQS queue.
:param queue_url: The URL of the queue.
:return: The ARN of the queue.
:raises ClientError: If getting queue attributes fails.
"""
try:
response = self.sqs_client.get_queue_attributes(
QueueUrl=queue_url,
AttributeNames=['QueueArn']
)
queue_arn = response['Attributes']['QueueArn']
logger.info(f"Queue ARN for {queue_url}: {queue_arn}")
return queue_arn
except ClientError as e:
error_code = e.response.get('Error', {}).get('Code', 'Unknown')
logger.error(f"Error getting queue ARN: {error_code} - {e}")
raise
def set_queue_policy_for_topic(self, queue_arn: str, topic_arn: str, queue_url: str) -> bool:
"""
Set the queue policy to allow SNS to send messages to the queue.
:param queue_arn: The ARN of the SQS queue.
:param topic_arn: The ARN of the SNS topic.
:param queue_url: The URL of the SQS queue.
:return: True if successful.
:raises ClientError: If setting the queue policy fails.
"""
try:
# Create policy that allows SNS to send messages to the queue
policy = {
"Version":"2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Principal": {
"Service": "sns.amazonaws.com"
},
"Action": "sqs:SendMessage",
"Resource": queue_arn,
"Condition": {
"ArnEquals": {
"aws:SourceArn": topic_arn
}
}
}
]
}
self.sqs_client.set_queue_attributes(
QueueUrl=queue_url,
Attributes={
'Policy': json.dumps(policy)
}
)
logger.info(f"Set queue policy for {queue_url} to allow messages from {topic_arn}")
return True
except ClientError as e:
error_code = e.response.get('Error', {}).get('Code', 'Unknown')
logger.error(f"Error setting queue policy: {error_code} - {e}")
raise
def receive_messages(self, queue_url: str, max_messages: int = 10) -> List[Dict[str, Any]]:
"""
Receive messages from an SQS queue.
:param queue_url: The URL of the queue to receive messages from.
:param max_messages: Maximum number of messages to receive (1-10).
:return: List of received messages.
:raises ClientError: If receiving messages fails.
"""
try:
# Ensure max_messages is within valid range
max_messages = max(1, min(10, max_messages))
response = self.sqs_client.receive_message(
QueueUrl=queue_url,
MaxNumberOfMessages=max_messages,
WaitTimeSeconds=2, # Short polling
MessageAttributeNames=['All']
)
messages = response.get('Messages', [])
logger.info(f"Received {len(messages)} messages from {queue_url}")
return messages
except ClientError as e:
error_code = e.response.get('Error', {}).get('Code', 'Unknown')
logger.error(f"Error receiving messages: {error_code} - {e}")
raise
def delete_messages(self, queue_url: str, messages: List[Dict[str, Any]]) -> bool:
"""
Delete messages from an SQS queue in batches.
:param queue_url: The URL of the queue.
:param messages: List of messages to delete.
:return: True if successful.
:raises ClientError: If deleting messages fails.
"""
try:
if not messages:
return True
# Build delete entries for batch delete
delete_entries = []
for i, message in enumerate(messages):
delete_entries.append({
'Id': str(i),
'ReceiptHandle': message['ReceiptHandle']
})
# Delete messages in batches of 10 (SQS limit)
batch_size = 10
for i in range(0, len(delete_entries), batch_size):
batch = delete_entries[i:i + batch_size]
response = self.sqs_client.delete_message_batch(
QueueUrl=queue_url,
Entries=batch
)
# Check for failures
if 'Failed' in response and response['Failed']:
for failed in response['Failed']:
logger.warning(f"Failed to delete message: {failed}")
logger.info(f"Deleted {len(messages)} messages from {queue_url}")
return True
except ClientError as e:
error_code = e.response.get('Error', {}).get('Code', 'Unknown')
logger.error(f"Error deleting messages: {error_code} - {e}")
raise
def delete_queue(self, queue_url: str) -> bool:
"""
Delete an SQS queue.
:param queue_url: The URL of the queue to delete.
:return: True if successful.
:raises ClientError: If the queue deletion fails.
"""
try:
self.sqs_client.delete_queue(QueueUrl=queue_url)
logger.info(f"Deleted queue: {queue_url}")
return True
except ClientError as e:
error_code = e.response.get('Error', {}).get('Code', 'Unknown')
if error_code == 'AWS.SimpleQueueService.NonExistentQueue':
logger.warning(f"Queue not found: {queue_url}")
return True # Already deleted
else:
logger.error(f"Error deleting queue: {error_code} - {e}")
raise
def list_queues(self, queue_name_prefix: Optional[str] = None) -> List[str]:
"""
List all SQS queues in the account using pagination.
:param queue_name_prefix: Optional prefix to filter queue names.
:return: List of queue URLs.
:raises ClientError: If listing queues fails.
"""
try:
queue_urls = []
paginator = self.sqs_client.get_paginator('list_queues')
page_params = {}
if queue_name_prefix:
page_params['QueueNamePrefix'] = queue_name_prefix
for page in paginator.paginate(**page_params):
queue_urls.extend(page.get('QueueUrls', []))
logger.info(f"Found {len(queue_urls)} queues")
return queue_urls
except ClientError as e:
error_code = e.response.get('Error', {}).get('Code', 'Unknown')
if error_code == 'AccessDenied':
logger.error("Access denied listing queues - check IAM permissions")
else:
logger.error(f"Error listing queues: {error_code} - {e}")
raise
def send_message(self, queue_url: str, message_body: str, **kwargs) -> str:
"""
Send a message to an SQS queue.
:param queue_url: The URL of the queue.
:param message_body: The message content.
:param kwargs: Additional message parameters (DelaySeconds, MessageAttributes, etc.).
:return: The message ID.
:raises ClientError: If sending the message fails.
"""
try:
send_params = {
'QueueUrl': queue_url,
'MessageBody': message_body,
**kwargs
}
response = self.sqs_client.send_message(**send_params)
message_id = response['MessageId']
logger.info(f"Sent message to {queue_url} with ID: {message_id}")
return message_id
except ClientError as e:
error_code = e.response.get('Error', {}).get('Code', 'Unknown')
logger.error(f"Error sending message: {error_code} - {e}")
raise
```
+ 有关 API 详细信息，请参阅《AWS SDK for Python (Boto3) API Reference》**中的以下主题。
+ [CreateQueue](https://docs.aws.amazon.com/goto/boto3/sqs-2012-11-05/CreateQueue)
+ [CreateTopic](https://docs.aws.amazon.com/goto/boto3/sns-2010-03-31/CreateTopic)
+ [DeleteMessageBatch](https://docs.aws.amazon.com/goto/boto3/sqs-2012-11-05/DeleteMessageBatch)
+ [DeleteQueue](https://docs.aws.amazon.com/goto/boto3/sqs-2012-11-05/DeleteQueue)
+ [DeleteTopic](https://docs.aws.amazon.com/goto/boto3/sns-2010-03-31/DeleteTopic)
+ [GetQueueAttributes](https://docs.aws.amazon.com/goto/boto3/sqs-2012-11-05/GetQueueAttributes)
+ [发布](https://docs.aws.amazon.com/goto/boto3/sns-2010-03-31/Publish)
+ [ReceiveMessage](https://docs.aws.amazon.com/goto/boto3/sqs-2012-11-05/ReceiveMessage)
+ [SetQueueAttributes](https://docs.aws.amazon.com/goto/boto3/sqs-2012-11-05/SetQueueAttributes)
+ [Subscribe](https://docs.aws.amazon.com/goto/boto3/sns-2010-03-31/Subscribe)
+ [Unsubscribe](https://docs.aws.amazon.com/goto/boto3/sns-2010-03-31/Unsubscribe)
### 发送和接收批量消息
以下代码示例展示了如何：
+ 创建 Amazon SQS 队列。
+ 将成批消息发送到队列。
+ 从队列中接收成批消息。
+ 从队列中删除成批消息。
**适用于 Python 的 SDK（Boto3）**
还有更多相关信息 GitHub。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/sqs#code-examples)中查找完整示例，了解如何进行设置和运行。
创建函数来包装 Amazon SQS 消息函数。
```
import logging
import sys
import boto3
from botocore.exceptions import ClientError
import queue_wrapper
logger = logging.getLogger(__name__)
sqs = boto3.resource("sqs")
def send_messages(queue, messages):
"""
Send a batch of messages in a single request to an SQS queue.
This request may return overall success even when some messages were not sent.
The caller must inspect the Successful and Failed lists in the response and
resend any failed messages.
:param queue: The queue to receive the messages.
:param messages: The messages to send to the queue. These are simplified to
contain only the message body and attributes.
:return: The response from SQS that contains the list of successful and failed
messages.
"""
try:
entries = [
{
"Id": str(ind),
"MessageBody": msg["body"],
"MessageAttributes": msg["attributes"],
}
for ind, msg in enumerate(messages)
]
response = queue.send_messages(Entries=entries)
if "Successful" in response:
for msg_meta in response["Successful"]:
logger.info(
"Message sent: %s: %s",
msg_meta["MessageId"],
messages[int(msg_meta["Id"])]["body"],
)
if "Failed" in response:
for msg_meta in response["Failed"]:
logger.warning(
"Failed to send: %s: %s",
msg_meta["MessageId"],
messages[int(msg_meta["Id"])]["body"],
)
except ClientError as error:
logger.exception("Send messages failed to queue: %s", queue)
raise error
else:
return response
def receive_messages(queue, max_number, wait_time):
"""
Receive a batch of messages in a single request from an SQS queue.
:param queue: The queue from which to receive messages.
:param max_number: The maximum number of messages to receive. The actual number
of messages received might be less.
:param wait_time: The maximum time to wait (in seconds) before returning. When
this number is greater than zero, long polling is used. This
can result in reduced costs and fewer false empty responses.
:return: The list of Message objects received. These each contain the body
of the message and metadata and custom attributes.
"""
try:
messages = queue.receive_messages(
MessageAttributeNames=["All"],
MaxNumberOfMessages=max_number,
WaitTimeSeconds=wait_time,
)
for msg in messages:
logger.info("Received message: %s: %s", msg.message_id, msg.body)
except ClientError as error:
logger.exception("Couldn't receive messages from queue: %s", queue)
raise error
else:
return messages
def delete_messages(queue, messages):
"""
Delete a batch of messages from a queue in a single request.
:param queue: The queue from which to delete the messages.
:param messages: The list of messages to delete.
:return: The response from SQS that contains the list of successful and failed
message deletions.
"""
try:
entries = [
{"Id": str(ind), "ReceiptHandle": msg.receipt_handle}
for ind, msg in enumerate(messages)
]
response = queue.delete_messages(Entries=entries)
if "Successful" in response:
for msg_meta in response["Successful"]:
logger.info("Deleted %s", messages[int(msg_meta["Id"])].receipt_handle)
if "Failed" in response:
for msg_meta in response["Failed"]:
logger.warning(
"Could not delete %s", messages[int(msg_meta["Id"])].receipt_handle
)
except ClientError:
logger.exception("Couldn't delete messages from queue %s", queue)
else:
return response
```
使用包装器函数批量发送和接收消息。
```
def usage_demo():
"""
Shows how to:
* Read the lines from this Python file and send the lines in
batches of 10 as messages to a queue.
* Receive the messages in batches until the queue is empty.
* Reassemble the lines of the file and verify they match the original file.
"""
def pack_message(msg_path, msg_body, msg_line):
return {
"body": msg_body,
"attributes": {
"path": {"StringValue": msg_path, "DataType": "String"},
"line": {"StringValue": str(msg_line), "DataType": "String"},
},
}
def unpack_message(msg):
return (
msg.message_attributes["path"]["StringValue"],
msg.body,
int(msg.message_attributes["line"]["StringValue"]),
)
print("-" * 88)
print("Welcome to the Amazon Simple Queue Service (Amazon SQS) demo!")
print("-" * 88)
queue = queue_wrapper.create_queue("sqs-usage-demo-message-wrapper")
with open(__file__) as file:
lines = file.readlines()
line = 0
batch_size = 10
received_lines = [None] * len(lines)
print(f"Sending file lines in batches of {batch_size} as messages.")
while line < len(lines):
messages = [
pack_message(__file__, lines[index], index)
for index in range(line, min(line + batch_size, len(lines)))
]
line = line + batch_size
send_messages(queue, messages)
print(".", end="")
sys.stdout.flush()
print(f"Done. Sent {len(lines) - 1} messages.")
print(f"Receiving, handling, and deleting messages in batches of {batch_size}.")
more_messages = True
while more_messages:
received_messages = receive_messages(queue, batch_size, 2)
print(".", end="")
sys.stdout.flush()
for message in received_messages:
path, body, line = unpack_message(message)
received_lines[line] = body
if received_messages:
delete_messages(queue, received_messages)
else:
more_messages = False
print("Done.")
if all([lines[index] == received_lines[index] for index in range(len(lines))]):
print(f"Successfully reassembled all file lines!")
else:
print(f"Uh oh, some lines were missed!")
queue.delete()
print("Thanks for watching!")
print("-" * 88)
```
+ 有关 API 详细信息，请参阅《AWS SDK for Python (Boto3) API Reference》**中的以下主题。
+ [CreateQueue](https://docs.aws.amazon.com/goto/boto3/sqs-2012-11-05/CreateQueue)
+ [DeleteMessage](https://docs.aws.amazon.com/goto/boto3/sqs-2012-11-05/DeleteMessage)
+ [DeleteMessageBatch](https://docs.aws.amazon.com/goto/boto3/sqs-2012-11-05/DeleteMessageBatch)
+ [DeleteQueue](https://docs.aws.amazon.com/goto/boto3/sqs-2012-11-05/DeleteQueue)
+ [ReceiveMessage](https://docs.aws.amazon.com/goto/boto3/sqs-2012-11-05/ReceiveMessage)
+ [SendMessage](https://docs.aws.amazon.com/goto/boto3/sqs-2012-11-05/SendMessage)
+ [SendMessageBatch](https://docs.aws.amazon.com/goto/boto3/sqs-2012-11-05/SendMessageBatch)
## 无服务器示例
### 通过 Amazon SQS 触发器调用 Lambda 函数
以下代码示例展示了如何实现一个 Lambda 函数，该函数接收因接收来自 SNS 队列的消息而触发的事件。该函数从事件参数检索消息并记录每条消息的内容。
**适用于 Python 的 SDK（Boto3）**
还有更多相关信息 GitHub。在[无服务器示例](https://github.com/aws-samples/serverless-snippets/tree/main/integration-sqs-to-lambda)存储库中查找完整示例，并了解如何进行设置和运行。
使用 Python 将 SQS 事件与 Lambda 结合使用。
```
# Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
# SPDX-License-Identifier: Apache-2.0
def lambda_handler(event, context):
for message in event['Records']:
process_message(message)
print("done")
def process_message(message):
try:
print(f"Processed message {message['body']}")
# TODO: Do interesting work based on the new message
except Exception as err:
print("An error occurred")
raise err
```
### 报告使用 Amazon SQS 触发器进行 Lambda 函数批处理项目失败
以下代码示例展示了如何为接收来自 SQS 队列的事件的 Lambda 函数实现部分批处理响应。该函数在响应中报告批处理项目失败，并指示 Lambda 稍后重试这些消息。
**适用于 Python 的 SDK（Boto3）**
还有更多相关信息 GitHub。在[无服务器示例](https://github.com/aws-samples/serverless-snippets/tree/main/lambda-function-sqs-report-batch-item-failures)存储库中查找完整示例，并了解如何进行设置和运行。
报告使用 Python 进行 Lambda SQS 批处理项目失败。
```
# Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
# SPDX-License-Identifier: Apache-2.0
def lambda_handler(event, context):
if event:
batch_item_failures = []
sqs_batch_response = {}
for record in event["Records"]:
try:
print(f"Processed message: {record['body']}")
except Exception as e:
batch_item_failures.append({"itemIdentifier": record['messageId']})
sqs_batch_response["batchItemFailures"] = batch_item_failures
return sqs_batch_response
```