SQSEsempi di Amazon che utilizzano SDK per Python (Boto3)

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

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

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

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

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

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

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 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

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

Mostra come usare AWS SDK for Python (Boto3) with per creare un'applicazione di messaggistica che AWS Step Functions recupera i record dei messaggi da una tabella Amazon DynamoDB e li invia con Amazon Simple Queue Service (Amazon). SQS La macchina a stati si integra con una AWS Lambda funzione per la scansione del database alla ricerca di messaggi non inviati.

Per il codice sorgente completo e le istruzioni su come configurarlo ed eseguirlo, guarda l'esempio completo su. GitHub

Mostra come utilizzarlo AWS SDK for Python (Boto3) con Amazon Textract per rilevare elementi di testo, moduli e tabelle nell'immagine di un documento. L'immagine di input e l'output di Amazon Textract sono mostrati in un'applicazione Tkinter che consente di esplorare gli elementi rilevati.

Per il codice sorgente completo e le istruzioni su come configurarlo ed eseguirlo, guarda l'esempio completo su. GitHub

Crea un SNS FIFO argomento Amazon, sottoscrivi Amazon SQS FIFO e le code standard all'argomento e pubblica un messaggio sull'argomento.

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),
                },
            )
            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

Crea funzioni per racchiudere le funzioni dei SQS messaggi di Amazon.

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

Usa le funzioni wrapper per inviare e ricevere messaggi in batch.

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)

Consumo di un SQS evento con Lambda usando Python.

# 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

Segnalazione degli errori degli elementi SQS batch con Lambda utilizzando Python.

# 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:
                # process message
            except Exception as e:
                batch_item_failures.append({"itemIdentifier": record['messageId']})
        
        sqs_batch_response["batchItemFailures"] = batch_item_failures
        return sqs_batch_response