Amazon Keyspaces-Beispiele SDK für die Verwendung von Python (Boto3)

import boto3


def hello_keyspaces(keyspaces_client):
    """
    Use the AWS SDK for Python (Boto3) to create an Amazon Keyspaces (for Apache Cassandra)
    client and list the keyspaces in your account.
    This example uses the default settings specified in your shared credentials
    and config files.

    :param keyspaces_client: A Boto3 Amazon Keyspaces Client object. This object wraps
                             the low-level Amazon Keyspaces service API.
    """
    print("Hello, Amazon Keyspaces! Let's list some of your keyspaces:\n")
    for ks in keyspaces_client.list_keyspaces(maxResults=5).get("keyspaces", []):
        print(ks["keyspaceName"])
        print(f"\t{ks['resourceArn']}")


if __name__ == "__main__":
    hello_keyspaces(boto3.client("keyspaces"))

Führen Sie ein interaktives Szenario an einer Eingabeaufforderung aus.

class KeyspaceScenario:
    """Runs an interactive scenario that shows how to get started using Amazon Keyspaces."""

    def __init__(self, ks_wrapper):
        """
        :param ks_wrapper: An object that wraps Amazon Keyspace actions.
        """
        self.ks_wrapper = ks_wrapper

    @demo_func
    def create_keyspace(self):
        """
        1. Creates a keyspace.
        2. Lists up to 10 keyspaces in your account.
        """
        print("Let's create a keyspace.")
        ks_name = q.ask(
            "Enter a name for your new keyspace.\nThe name can contain only letters, "
            "numbers and underscores: ",
            q.non_empty,
        )
        if self.ks_wrapper.exists_keyspace(ks_name):
            print(f"A keyspace named {ks_name} exists.")
        else:
            ks_arn = self.ks_wrapper.create_keyspace(ks_name)
            ks_exists = False
            while not ks_exists:
                wait(3)
                ks_exists = self.ks_wrapper.exists_keyspace(ks_name)
            print(f"Created a new keyspace.\n\t{ks_arn}.")
        print("The first 10 keyspaces in your account are:\n")
        self.ks_wrapper.list_keyspaces(10)

    @demo_func
    def create_table(self):
        """
        1. Creates a table in the keyspace. The table is configured with a schema to hold
           movie data and has point-in-time recovery enabled.
        2. Waits for the table to be in an active state.
        3. Displays schema information for the table.
        4. Lists tables in the keyspace.
        """
        print("Let's create a table for movies in your keyspace.")
        table_name = q.ask("Enter a name for your table: ", q.non_empty)
        table = self.ks_wrapper.get_table(table_name)
        if table is not None:
            print(
                f"A table named {table_name} already exists in keyspace "
                f"{self.ks_wrapper.ks_name}."
            )
        else:
            table_arn = self.ks_wrapper.create_table(table_name)
            print(f"Created table {table_name}:\n\t{table_arn}")
            table = {"status": None}
            print("Waiting for your table to be ready...")
            while table["status"] != "ACTIVE":
                wait(5)
                table = self.ks_wrapper.get_table(table_name)
        print(f"Your table is {table['status']}. Its schema is:")
        pp(table["schemaDefinition"])
        print("\nThe tables in your keyspace are:\n")
        self.ks_wrapper.list_tables()

    @demo_func
    def ensure_tls_cert(self):
        """
        Ensures you have a TLS certificate available to use to secure the connection
        to the keyspace. This function downloads a default certificate or lets you
        specify your own.
        """
        print("To connect to your keyspace, you must have a TLS certificate.")
        print("Checking for TLS certificate...")
        cert_path = os.path.join(
            os.path.dirname(__file__), QueryManager.DEFAULT_CERT_FILE
        )
        if not os.path.exists(cert_path):
            cert_choice = q.ask(
                f"Press enter to download a certificate from {QueryManager.CERT_URL} "
                f"or enter the full path to the certificate you want to use: "
            )
            if cert_choice:
                cert_path = cert_choice
            else:
                cert = requests.get(QueryManager.CERT_URL).text
                with open(cert_path, "w") as cert_file:
                    cert_file.write(cert)
        else:
            q.ask(f"Certificate {cert_path} found. Press Enter to continue.")
        print(
            f"Certificate {cert_path} will be used to secure the connection to your keyspace."
        )
        return cert_path

    @demo_func
    def query_table(self, qm, movie_file):
        """
        1. Adds movies to the table from a sample movie data file.
        2. Gets a list of movies from the table and lets you select one.
        3. Displays more information about the selected movie.
        """
        qm.add_movies(self.ks_wrapper.table_name, movie_file)
        movies = qm.get_movies(self.ks_wrapper.table_name)
        print(f"Added {len(movies)} movies to the table:")
        sel = q.choose("Pick one to learn more about it: ", [m.title for m in movies])
        movie_choice = qm.get_movie(
            self.ks_wrapper.table_name, movies[sel].title, movies[sel].year
        )
        print(movie_choice.title)
        print(f"\tReleased: {movie_choice.release_date}")
        print(f"\tPlot: {movie_choice.plot}")

    @demo_func
    def update_and_restore_table(self, qm):
        """
        1. Updates the table by adding a column to track watched movies.
        2. Marks some of the movies as watched.
        3. Gets the list of watched movies from the table.
        4. Restores to a movies_restored table at a previous point in time.
        5. Gets the list of movies from the restored table.
        """
        print("Let's add a column to record which movies you've watched.")
        pre_update_timestamp = datetime.utcnow()
        print(
            f"Recorded the current UTC time of {pre_update_timestamp} so we can restore the table later."
        )
        self.ks_wrapper.update_table()
        print("Waiting for your table to update...")
        table = {"status": "UPDATING"}
        while table["status"] != "ACTIVE":
            wait(5)
            table = self.ks_wrapper.get_table(self.ks_wrapper.table_name)
        print("Column 'watched' added to table.")
        q.ask(
            "Let's mark some of the movies as watched. Press Enter when you're ready.\n"
        )
        movies = qm.get_movies(self.ks_wrapper.table_name)
        for movie in movies[:10]:
            qm.watched_movie(self.ks_wrapper.table_name, movie.title, movie.year)
            print(f"Marked {movie.title} as watched.")
        movies = qm.get_movies(self.ks_wrapper.table_name, watched=True)
        print("-" * 88)
        print("The watched movies in our table are:\n")
        for movie in movies:
            print(movie.title)
        print("-" * 88)
        if q.ask(
            "Do you want to restore the table to the way it was before all of these\n"
            "updates? Keep in mind, this can take up to 20 minutes. (y/n) ",
            q.is_yesno,
        ):
            starting_table_name = self.ks_wrapper.table_name
            table_name_restored = self.ks_wrapper.restore_table(pre_update_timestamp)
            table = {"status": "RESTORING"}
            while table["status"] != "ACTIVE":
                wait(10)
                table = self.ks_wrapper.get_table(table_name_restored)
            print(
                f"Restored {starting_table_name} to {table_name_restored} "
                f"at a point in time of {pre_update_timestamp}."
            )
            movies = qm.get_movies(table_name_restored)
            print("Now the movies in our table are:")
            for movie in movies:
                print(movie.title)

    def cleanup(self, cert_path):
        """
        1. Deletes the table and waits for it to be removed.
        2. Deletes the keyspace.

        :param cert_path: The path of the TLS certificate used in the demo. If the
                          certificate was downloaded during the demo, it is removed.
        """
        if q.ask(
            f"Do you want to delete your {self.ks_wrapper.table_name} table and "
            f"{self.ks_wrapper.ks_name} keyspace? (y/n) ",
            q.is_yesno,
        ):
            table_name = self.ks_wrapper.table_name
            self.ks_wrapper.delete_table()
            table = self.ks_wrapper.get_table(table_name)
            print("Waiting for the table to be deleted.")
            while table is not None:
                wait(5)
                table = self.ks_wrapper.get_table(table_name)
            print("Table deleted.")
            self.ks_wrapper.delete_keyspace()
            print(
                "Keyspace deleted. If you chose to restore your table during the "
                "demo, the original table is also deleted."
            )
            if cert_path == os.path.join(
                os.path.dirname(__file__), QueryManager.DEFAULT_CERT_FILE
            ) and os.path.exists(cert_path):
                os.remove(cert_path)
                print("Removed certificate that was downloaded for this demo.")

    def run_scenario(self):
        logging.basicConfig(level=logging.INFO, format="%(levelname)s: %(message)s")

        print("-" * 88)
        print("Welcome to the Amazon Keyspaces (for Apache Cassandra) demo.")
        print("-" * 88)

        self.create_keyspace()
        self.create_table()
        cert_file_path = self.ensure_tls_cert()
        # Use a context manager to ensure the connection to the keyspace is closed.
        with QueryManager(
            cert_file_path, boto3.DEFAULT_SESSION, self.ks_wrapper.ks_name
        ) as qm:
            self.query_table(qm, "../../../resources/sample_files/movies.json")
            self.update_and_restore_table(qm)
        self.cleanup(cert_file_path)

        print("\nThanks for watching!")
        print("-" * 88)


if __name__ == "__main__":
    try:
        scenario = KeyspaceScenario(KeyspaceWrapper.from_client())
        scenario.run_scenario()
    except Exception:
        logging.exception("Something went wrong with the demo.")

Definieren Sie eine Klasse, die Schlüsselraum- und Tabellenaktionen umschließt.

class KeyspaceWrapper:
    """Encapsulates Amazon Keyspaces (for Apache Cassandra) keyspace and table actions."""

    def __init__(self, keyspaces_client):
        """
        :param keyspaces_client: A Boto3 Amazon Keyspaces client.
        """
        self.keyspaces_client = keyspaces_client
        self.ks_name = None
        self.ks_arn = None
        self.table_name = None

    @classmethod
    def from_client(cls):
        keyspaces_client = boto3.client("keyspaces")
        return cls(keyspaces_client)


    def create_keyspace(self, name):
        """
        Creates a keyspace.

        :param name: The name to give the keyspace.
        :return: The Amazon Resource Name (ARN) of the new keyspace.
        """
        try:
            response = self.keyspaces_client.create_keyspace(keyspaceName=name)
            self.ks_name = name
            self.ks_arn = response["resourceArn"]
        except ClientError as err:
            logger.error(
                "Couldn't create %s. Here's why: %s: %s",
                name,
                err.response["Error"]["Code"],
                err.response["Error"]["Message"],
            )
            raise
        else:
            return self.ks_arn


    def exists_keyspace(self, name):
        """
        Checks whether a keyspace exists.

        :param name: The name of the keyspace to look up.
        :return: True when the keyspace exists. Otherwise, False.
        """
        try:
            response = self.keyspaces_client.get_keyspace(keyspaceName=name)
            self.ks_name = response["keyspaceName"]
            self.ks_arn = response["resourceArn"]
            exists = True
        except ClientError as err:
            if err.response["Error"]["Code"] == "ResourceNotFoundException":
                logger.info("Keyspace %s does not exist.", name)
                exists = False
            else:
                logger.error(
                    "Couldn't verify %s exists. Here's why: %s: %s",
                    name,
                    err.response["Error"]["Code"],
                    err.response["Error"]["Message"],
                )
                raise
        return exists


    def list_keyspaces(self, limit):
        """
        Lists the keyspaces in your account.

        :param limit: The maximum number of keyspaces to list.
        """
        try:
            ks_paginator = self.keyspaces_client.get_paginator("list_keyspaces")
            for page in ks_paginator.paginate(PaginationConfig={"MaxItems": limit}):
                for ks in page["keyspaces"]:
                    print(ks["keyspaceName"])
                    print(f"\t{ks['resourceArn']}")
        except ClientError as err:
            logger.error(
                "Couldn't list keyspaces. Here's why: %s: %s",
                err.response["Error"]["Code"],
                err.response["Error"]["Message"],
            )
            raise


    def create_table(self, table_name):
        """
        Creates a table in the  keyspace.
        The table is created with a schema for storing movie data
        and has point-in-time recovery enabled.

        :param table_name: The name to give the table.
        :return: The ARN of the new table.
        """
        try:
            response = self.keyspaces_client.create_table(
                keyspaceName=self.ks_name,
                tableName=table_name,
                schemaDefinition={
                    "allColumns": [
                        {"name": "title", "type": "text"},
                        {"name": "year", "type": "int"},
                        {"name": "release_date", "type": "timestamp"},
                        {"name": "plot", "type": "text"},
                    ],
                    "partitionKeys": [{"name": "year"}, {"name": "title"}],
                },
                pointInTimeRecovery={"status": "ENABLED"},
            )
        except ClientError as err:
            logger.error(
                "Couldn't create table %s. Here's why: %s: %s",
                table_name,
                err.response["Error"]["Code"],
                err.response["Error"]["Message"],
            )
            raise
        else:
            return response["resourceArn"]


    def get_table(self, table_name):
        """
        Gets data about a table in the keyspace.

        :param table_name: The name of the table to look up.
        :return: Data about the table.
        """
        try:
            response = self.keyspaces_client.get_table(
                keyspaceName=self.ks_name, tableName=table_name
            )
            self.table_name = table_name
        except ClientError as err:
            if err.response["Error"]["Code"] == "ResourceNotFoundException":
                logger.info("Table %s does not exist.", table_name)
                self.table_name = None
                response = None
            else:
                logger.error(
                    "Couldn't verify %s exists. Here's why: %s: %s",
                    table_name,
                    err.response["Error"]["Code"],
                    err.response["Error"]["Message"],
                )
                raise
        return response


    def list_tables(self):
        """
        Lists the tables in the keyspace.
        """
        try:
            table_paginator = self.keyspaces_client.get_paginator("list_tables")
            for page in table_paginator.paginate(keyspaceName=self.ks_name):
                for table in page["tables"]:
                    print(table["tableName"])
                    print(f"\t{table['resourceArn']}")
        except ClientError as err:
            logger.error(
                "Couldn't list tables in keyspace %s. Here's why: %s: %s",
                self.ks_name,
                err.response["Error"]["Code"],
                err.response["Error"]["Message"],
            )
            raise


    def update_table(self):
        """
        Updates the schema of the table.

        This example updates a table of movie data by adding a new column
        that tracks whether the movie has been watched.
        """
        try:
            self.keyspaces_client.update_table(
                keyspaceName=self.ks_name,
                tableName=self.table_name,
                addColumns=[{"name": "watched", "type": "boolean"}],
            )
        except ClientError as err:
            logger.error(
                "Couldn't update table %s. Here's why: %s: %s",
                self.table_name,
                err.response["Error"]["Code"],
                err.response["Error"]["Message"],
            )
            raise


    def restore_table(self, restore_timestamp):
        """
        Restores the table to a previous point in time. The table is restored
        to a new table in the same keyspace.

        :param restore_timestamp: The point in time to restore the table. This time
                                  must be in UTC format.
        :return: The name of the restored table.
        """
        try:
            restored_table_name = f"{self.table_name}_restored"
            self.keyspaces_client.restore_table(
                sourceKeyspaceName=self.ks_name,
                sourceTableName=self.table_name,
                targetKeyspaceName=self.ks_name,
                targetTableName=restored_table_name,
                restoreTimestamp=restore_timestamp,
            )
        except ClientError as err:
            logger.error(
                "Couldn't restore table %s. Here's why: %s: %s",
                restore_timestamp,
                err.response["Error"]["Code"],
                err.response["Error"]["Message"],
            )
            raise
        else:
            return restored_table_name


    def delete_table(self):
        """
        Deletes the table from the keyspace.
        """
        try:
            self.keyspaces_client.delete_table(
                keyspaceName=self.ks_name, tableName=self.table_name
            )
            self.table_name = None
        except ClientError as err:
            logger.error(
                "Couldn't delete table %s. Here's why: %s: %s",
                self.table_name,
                err.response["Error"]["Code"],
                err.response["Error"]["Message"],
            )
            raise


    def delete_keyspace(self):
        """
        Deletes the keyspace.
        """
        try:
            self.keyspaces_client.delete_keyspace(keyspaceName=self.ks_name)
            self.ks_name = None
        except ClientError as err:
            logger.error(
                "Couldn't delete keyspace %s. Here's why: %s: %s",
                self.ks_name,
                err.response["Error"]["Code"],
                err.response["Error"]["Message"],
            )
            raise

Definieren Sie eine Klasse, die eine TLS Verbindung zu einem Schlüsselraum herstellt, sich mit Sigv4 authentifiziert und CQL Abfragen an eine Tabelle im Schlüsselraum sendet.

class QueryManager:
    """
    Manages queries to an Amazon Keyspaces (for Apache Cassandra) keyspace.
    Queries are secured by TLS and authenticated by using the Signature V4 (SigV4)
    AWS signing protocol. This is more secure than sending username and password
    with a plain-text authentication provider.

    This example downloads a default certificate to secure TLS, or lets you specify
    your own.

    This example uses a table of movie data to demonstrate basic queries.
    """

    DEFAULT_CERT_FILE = "sf-class2-root.crt"
    CERT_URL = f"https://certs.secureserver.net/repository/sf-class2-root.crt"

    def __init__(self, cert_file_path, boto_session, keyspace_name):
        """
        :param cert_file_path: The path and file name of the certificate used for TLS.
        :param boto_session: A Boto3 session. This is used to acquire your AWS credentials.
        :param keyspace_name: The name of the keyspace to connect.
        """
        self.cert_file_path = cert_file_path
        self.boto_session = boto_session
        self.ks_name = keyspace_name
        self.cluster = None
        self.session = None

    def __enter__(self):
        """
        Creates a session connection to the keyspace that is secured by TLS and
        authenticated by SigV4.
        """
        ssl_context = SSLContext(PROTOCOL_TLSv1_2)
        ssl_context.load_verify_locations(self.cert_file_path)
        ssl_context.verify_mode = CERT_REQUIRED
        auth_provider = SigV4AuthProvider(self.boto_session)
        contact_point = f"cassandra.{self.boto_session.region_name}.amazonaws.com"
        exec_profile = ExecutionProfile(
            consistency_level=ConsistencyLevel.LOCAL_QUORUM,
            load_balancing_policy=DCAwareRoundRobinPolicy(),
        )
        self.cluster = Cluster(
            [contact_point],
            ssl_context=ssl_context,
            auth_provider=auth_provider,
            port=9142,
            execution_profiles={EXEC_PROFILE_DEFAULT: exec_profile},
            protocol_version=4,
        )
        self.cluster.__enter__()
        self.session = self.cluster.connect(self.ks_name)
        return self

    def __exit__(self, *args):
        """
        Exits the cluster. This shuts down all existing session connections.
        """
        self.cluster.__exit__(*args)

    def add_movies(self, table_name, movie_file_path):
        """
        Gets movies from a JSON file and adds them to a table in the keyspace.

        :param table_name: The name of the table.
        :param movie_file_path: The path and file name of a JSON file that contains movie data.
        """
        with open(movie_file_path, "r") as movie_file:
            movies = json.loads(movie_file.read())
        stmt = self.session.prepare(
            f"INSERT INTO {table_name} (year, title, release_date, plot) VALUES (?, ?, ?, ?);"
        )
        for movie in movies[:20]:
            self.session.execute(
                stmt,
                parameters=[
                    movie["year"],
                    movie["title"],
                    date.fromisoformat(movie["info"]["release_date"].partition("T")[0]),
                    movie["info"]["plot"],
                ],
            )

    def get_movies(self, table_name, watched=None):
        """
        Gets the title and year of the full list of movies from the table.

        :param table_name: The name of the movie table.
        :param watched: When specified, the returned list of movies is filtered to
                        either movies that have been watched or movies that have not
                        been watched. Otherwise, all movies are returned.
        :return: A list of movies in the table.
        """
        if watched is None:
            stmt = SimpleStatement(f"SELECT title, year from {table_name}")
            params = None
        else:
            stmt = SimpleStatement(
                f"SELECT title, year from {table_name} WHERE watched = %s ALLOW FILTERING"
            )
            params = [watched]
        return self.session.execute(stmt, parameters=params).all()

    def get_movie(self, table_name, title, year):
        """
        Gets a single movie from the table, by title and year.

        :param table_name: The name of the movie table.
        :param title: The title of the movie.
        :param year: The year of the movie's release.
        :return: The requested movie.
        """
        return self.session.execute(
            SimpleStatement(
                f"SELECT * from {table_name} WHERE title = %s AND year = %s"
            ),
            parameters=[title, year],
        ).one()

    def watched_movie(self, table_name, title, year):
        """
        Updates a movie as having been watched.

        :param table_name: The name of the movie table.
        :param title: The title of the movie.
        :param year: The year of the movie's release.
        """
        self.session.execute(
            SimpleStatement(
                f"UPDATE {table_name} SET watched=true WHERE title = %s AND year = %s"
            ),
            parameters=[title, year],
        )

class KeyspaceWrapper:
    """Encapsulates Amazon Keyspaces (for Apache Cassandra) keyspace and table actions."""

    def __init__(self, keyspaces_client):
        """
        :param keyspaces_client: A Boto3 Amazon Keyspaces client.
        """
        self.keyspaces_client = keyspaces_client
        self.ks_name = None
        self.ks_arn = None
        self.table_name = None

    @classmethod
    def from_client(cls):
        keyspaces_client = boto3.client("keyspaces")
        return cls(keyspaces_client)


    def create_keyspace(self, name):
        """
        Creates a keyspace.

        :param name: The name to give the keyspace.
        :return: The Amazon Resource Name (ARN) of the new keyspace.
        """
        try:
            response = self.keyspaces_client.create_keyspace(keyspaceName=name)
            self.ks_name = name
            self.ks_arn = response["resourceArn"]
        except ClientError as err:
            logger.error(
                "Couldn't create %s. Here's why: %s: %s",
                name,
                err.response["Error"]["Code"],
                err.response["Error"]["Message"],
            )
            raise
        else:
            return self.ks_arn

class KeyspaceWrapper:
    """Encapsulates Amazon Keyspaces (for Apache Cassandra) keyspace and table actions."""

    def __init__(self, keyspaces_client):
        """
        :param keyspaces_client: A Boto3 Amazon Keyspaces client.
        """
        self.keyspaces_client = keyspaces_client
        self.ks_name = None
        self.ks_arn = None
        self.table_name = None

    @classmethod
    def from_client(cls):
        keyspaces_client = boto3.client("keyspaces")
        return cls(keyspaces_client)


    def create_table(self, table_name):
        """
        Creates a table in the  keyspace.
        The table is created with a schema for storing movie data
        and has point-in-time recovery enabled.

        :param table_name: The name to give the table.
        :return: The ARN of the new table.
        """
        try:
            response = self.keyspaces_client.create_table(
                keyspaceName=self.ks_name,
                tableName=table_name,
                schemaDefinition={
                    "allColumns": [
                        {"name": "title", "type": "text"},
                        {"name": "year", "type": "int"},
                        {"name": "release_date", "type": "timestamp"},
                        {"name": "plot", "type": "text"},
                    ],
                    "partitionKeys": [{"name": "year"}, {"name": "title"}],
                },
                pointInTimeRecovery={"status": "ENABLED"},
            )
        except ClientError as err:
            logger.error(
                "Couldn't create table %s. Here's why: %s: %s",
                table_name,
                err.response["Error"]["Code"],
                err.response["Error"]["Message"],
            )
            raise
        else:
            return response["resourceArn"]

class KeyspaceWrapper:
    """Encapsulates Amazon Keyspaces (for Apache Cassandra) keyspace and table actions."""

    def __init__(self, keyspaces_client):
        """
        :param keyspaces_client: A Boto3 Amazon Keyspaces client.
        """
        self.keyspaces_client = keyspaces_client
        self.ks_name = None
        self.ks_arn = None
        self.table_name = None

    @classmethod
    def from_client(cls):
        keyspaces_client = boto3.client("keyspaces")
        return cls(keyspaces_client)


    def delete_keyspace(self):
        """
        Deletes the keyspace.
        """
        try:
            self.keyspaces_client.delete_keyspace(keyspaceName=self.ks_name)
            self.ks_name = None
        except ClientError as err:
            logger.error(
                "Couldn't delete keyspace %s. Here's why: %s: %s",
                self.ks_name,
                err.response["Error"]["Code"],
                err.response["Error"]["Message"],
            )
            raise

class KeyspaceWrapper:
    """Encapsulates Amazon Keyspaces (for Apache Cassandra) keyspace and table actions."""

    def __init__(self, keyspaces_client):
        """
        :param keyspaces_client: A Boto3 Amazon Keyspaces client.
        """
        self.keyspaces_client = keyspaces_client
        self.ks_name = None
        self.ks_arn = None
        self.table_name = None

    @classmethod
    def from_client(cls):
        keyspaces_client = boto3.client("keyspaces")
        return cls(keyspaces_client)


    def delete_table(self):
        """
        Deletes the table from the keyspace.
        """
        try:
            self.keyspaces_client.delete_table(
                keyspaceName=self.ks_name, tableName=self.table_name
            )
            self.table_name = None
        except ClientError as err:
            logger.error(
                "Couldn't delete table %s. Here's why: %s: %s",
                self.table_name,
                err.response["Error"]["Code"],
                err.response["Error"]["Message"],
            )
            raise

class KeyspaceWrapper:
    """Encapsulates Amazon Keyspaces (for Apache Cassandra) keyspace and table actions."""

    def __init__(self, keyspaces_client):
        """
        :param keyspaces_client: A Boto3 Amazon Keyspaces client.
        """
        self.keyspaces_client = keyspaces_client
        self.ks_name = None
        self.ks_arn = None
        self.table_name = None

    @classmethod
    def from_client(cls):
        keyspaces_client = boto3.client("keyspaces")
        return cls(keyspaces_client)


    def exists_keyspace(self, name):
        """
        Checks whether a keyspace exists.

        :param name: The name of the keyspace to look up.
        :return: True when the keyspace exists. Otherwise, False.
        """
        try:
            response = self.keyspaces_client.get_keyspace(keyspaceName=name)
            self.ks_name = response["keyspaceName"]
            self.ks_arn = response["resourceArn"]
            exists = True
        except ClientError as err:
            if err.response["Error"]["Code"] == "ResourceNotFoundException":
                logger.info("Keyspace %s does not exist.", name)
                exists = False
            else:
                logger.error(
                    "Couldn't verify %s exists. Here's why: %s: %s",
                    name,
                    err.response["Error"]["Code"],
                    err.response["Error"]["Message"],
                )
                raise
        return exists

class KeyspaceWrapper:
    """Encapsulates Amazon Keyspaces (for Apache Cassandra) keyspace and table actions."""

    def __init__(self, keyspaces_client):
        """
        :param keyspaces_client: A Boto3 Amazon Keyspaces client.
        """
        self.keyspaces_client = keyspaces_client
        self.ks_name = None
        self.ks_arn = None
        self.table_name = None

    @classmethod
    def from_client(cls):
        keyspaces_client = boto3.client("keyspaces")
        return cls(keyspaces_client)


    def get_table(self, table_name):
        """
        Gets data about a table in the keyspace.

        :param table_name: The name of the table to look up.
        :return: Data about the table.
        """
        try:
            response = self.keyspaces_client.get_table(
                keyspaceName=self.ks_name, tableName=table_name
            )
            self.table_name = table_name
        except ClientError as err:
            if err.response["Error"]["Code"] == "ResourceNotFoundException":
                logger.info("Table %s does not exist.", table_name)
                self.table_name = None
                response = None
            else:
                logger.error(
                    "Couldn't verify %s exists. Here's why: %s: %s",
                    table_name,
                    err.response["Error"]["Code"],
                    err.response["Error"]["Message"],
                )
                raise
        return response

class KeyspaceWrapper:
    """Encapsulates Amazon Keyspaces (for Apache Cassandra) keyspace and table actions."""

    def __init__(self, keyspaces_client):
        """
        :param keyspaces_client: A Boto3 Amazon Keyspaces client.
        """
        self.keyspaces_client = keyspaces_client
        self.ks_name = None
        self.ks_arn = None
        self.table_name = None

    @classmethod
    def from_client(cls):
        keyspaces_client = boto3.client("keyspaces")
        return cls(keyspaces_client)


    def list_keyspaces(self, limit):
        """
        Lists the keyspaces in your account.

        :param limit: The maximum number of keyspaces to list.
        """
        try:
            ks_paginator = self.keyspaces_client.get_paginator("list_keyspaces")
            for page in ks_paginator.paginate(PaginationConfig={"MaxItems": limit}):
                for ks in page["keyspaces"]:
                    print(ks["keyspaceName"])
                    print(f"\t{ks['resourceArn']}")
        except ClientError as err:
            logger.error(
                "Couldn't list keyspaces. Here's why: %s: %s",
                err.response["Error"]["Code"],
                err.response["Error"]["Message"],
            )
            raise

class KeyspaceWrapper:
    """Encapsulates Amazon Keyspaces (for Apache Cassandra) keyspace and table actions."""

    def __init__(self, keyspaces_client):
        """
        :param keyspaces_client: A Boto3 Amazon Keyspaces client.
        """
        self.keyspaces_client = keyspaces_client
        self.ks_name = None
        self.ks_arn = None
        self.table_name = None

    @classmethod
    def from_client(cls):
        keyspaces_client = boto3.client("keyspaces")
        return cls(keyspaces_client)


    def list_tables(self):
        """
        Lists the tables in the keyspace.
        """
        try:
            table_paginator = self.keyspaces_client.get_paginator("list_tables")
            for page in table_paginator.paginate(keyspaceName=self.ks_name):
                for table in page["tables"]:
                    print(table["tableName"])
                    print(f"\t{table['resourceArn']}")
        except ClientError as err:
            logger.error(
                "Couldn't list tables in keyspace %s. Here's why: %s: %s",
                self.ks_name,
                err.response["Error"]["Code"],
                err.response["Error"]["Message"],
            )
            raise

class KeyspaceWrapper:
    """Encapsulates Amazon Keyspaces (for Apache Cassandra) keyspace and table actions."""

    def __init__(self, keyspaces_client):
        """
        :param keyspaces_client: A Boto3 Amazon Keyspaces client.
        """
        self.keyspaces_client = keyspaces_client
        self.ks_name = None
        self.ks_arn = None
        self.table_name = None

    @classmethod
    def from_client(cls):
        keyspaces_client = boto3.client("keyspaces")
        return cls(keyspaces_client)


    def restore_table(self, restore_timestamp):
        """
        Restores the table to a previous point in time. The table is restored
        to a new table in the same keyspace.

        :param restore_timestamp: The point in time to restore the table. This time
                                  must be in UTC format.
        :return: The name of the restored table.
        """
        try:
            restored_table_name = f"{self.table_name}_restored"
            self.keyspaces_client.restore_table(
                sourceKeyspaceName=self.ks_name,
                sourceTableName=self.table_name,
                targetKeyspaceName=self.ks_name,
                targetTableName=restored_table_name,
                restoreTimestamp=restore_timestamp,
            )
        except ClientError as err:
            logger.error(
                "Couldn't restore table %s. Here's why: %s: %s",
                restore_timestamp,
                err.response["Error"]["Code"],
                err.response["Error"]["Message"],
            )
            raise
        else:
            return restored_table_name

class KeyspaceWrapper:
    """Encapsulates Amazon Keyspaces (for Apache Cassandra) keyspace and table actions."""

    def __init__(self, keyspaces_client):
        """
        :param keyspaces_client: A Boto3 Amazon Keyspaces client.
        """
        self.keyspaces_client = keyspaces_client
        self.ks_name = None
        self.ks_arn = None
        self.table_name = None

    @classmethod
    def from_client(cls):
        keyspaces_client = boto3.client("keyspaces")
        return cls(keyspaces_client)


    def update_table(self):
        """
        Updates the schema of the table.

        This example updates a table of movie data by adding a new column
        that tracks whether the movie has been watched.
        """
        try:
            self.keyspaces_client.update_table(
                keyspaceName=self.ks_name,
                tableName=self.table_name,
                addColumns=[{"name": "watched", "type": "boolean"}],
            )
        except ClientError as err:
            logger.error(
                "Couldn't update table %s. Here's why: %s: %s",
                self.table_name,
                err.response["Error"]["Code"],
                err.response["Error"]["Message"],
            )
            raise