Core Connectivity

class Cluster:
    def __init__(
        self,
        contact_points=None,
        port=9042,
        executor_threads=2,
        auth_provider=None,
        load_balancing_policy=None,
        reconnection_policy=None,
        default_retry_policy=None,
        conviction_policy=None,
        metrics_enabled=False,
        connection_class=None,
        ssl_context=None,
        ssl_options=None,
        sockopts=None,
        cql_version=None,
        protocol_version=None,
        is_default_protocol_version=None,
        compression=True,
        max_schema_agreement_wait=10,
        control_connection_timeout=2.0,
        idle_heartbeat_interval=30,
        idle_heartbeat_timeout=60,
        schema_event_refresh_window=2,
        topology_event_refresh_window=10,
        status_event_refresh_window=2,
        prepare_on_all_hosts=True,
        reprepare_on_up=True,
        max_requests_per_connection=None,
        **kwargs
    ):
        """
        Initialize a Cluster instance to manage Cassandra connections.

        Parameters:
        - contact_points (list): List of host addresses to initially connect to
        - port (int): Port number for Cassandra connections (default: 9042)
        - executor_threads (int): Number of threads for I/O operations
        - auth_provider (AuthProvider): Authentication provider for credentials
        - load_balancing_policy (LoadBalancingPolicy): Policy for host selection
        - reconnection_policy (ReconnectionPolicy): Policy for reconnection delays
        - default_retry_policy (RetryPolicy): Default retry policy for failed operations
        - conviction_policy (ConvictionPolicy): Policy for marking hosts as failed
        - metrics_enabled (bool): Enable connection and request metrics
        - connection_class: Connection implementation class
        - ssl_context: SSL context for encrypted connections
        - ssl_options (dict): SSL configuration options
        - sockopts (list): Socket options tuples
        - cql_version (str): CQL version to use
        - protocol_version (int): Native protocol version (1-4)
        - compression (bool or str): Enable compression ('snappy', 'lz4', or True)
        - max_schema_agreement_wait (float): Max time to wait for schema agreement
        - control_connection_timeout (float): Timeout for control connection operations
        - idle_heartbeat_interval (float): Interval between heartbeat messages
        - idle_heartbeat_timeout (float): Timeout for heartbeat responses
        - prepare_on_all_hosts (bool): Prepare statements on all hosts
        - reprepare_on_up (bool): Re-prepare statements when hosts come back up
        - max_requests_per_connection (int): Max concurrent requests per connection
        """

    def connect(self, keyspace=None):
        """
        Create a new Session for this cluster.

        Parameters:
        - keyspace (str): Default keyspace for the session

        Returns:
        Session: A new session connected to the cluster
        """

    def shutdown(self):
        """
        Shut down this cluster and all associated sessions.
        Closes all connections and stops background threads.
        """

    def add_host(self, address, datacenter=None, rack=None, signal=True):
        """
        Add a host to the cluster.

        Parameters:
        - address (str): Host address to add
        - datacenter (str): Datacenter name
        - rack (str): Rack name  
        - signal (bool): Whether to signal policy changes
        """

    def remove_host(self, host):
        """
        Remove a host from the cluster.

        Parameters:
        - host (Host): Host object to remove
        """

    @property
    def metadata(self):
        """Metadata: Cluster metadata including keyspace and table information"""

    @property
    def metrics(self):
        """Metrics: Connection and request metrics if enabled"""

class Session:
    def execute(self, query, parameters=None, timeout=None, trace=False):
        """
        Execute a query synchronously.

        Parameters:
        - query (str or Statement): CQL query string or Statement object
        - parameters (list or dict): Query parameters for placeholder binding
        - timeout (float): Query timeout in seconds
        - trace (bool): Enable query tracing

        Returns:
        ResultSet: Query results with row data and metadata

        Raises:
        - Unavailable: Not enough replicas available
        - ReadTimeout: Read operation timed out
        - WriteTimeout: Write operation timed out
        - InvalidRequest: Invalid query or parameters
        """

    def execute_async(self, query, parameters=None, trace=False):
        """
        Execute a query asynchronously.

        Parameters:
        - query (str or Statement): CQL query string or Statement object
        - parameters (list or dict): Query parameters for placeholder binding
        - trace (bool): Enable query tracing

        Returns:
        ResponseFuture: Future object for asynchronous result handling
        """

    def prepare(self, query):
        """
        Prepare a query for efficient repeated execution.

        Parameters:
        - query (str): CQL query string with parameter placeholders

        Returns:
        PreparedStatement: Prepared statement object for binding and execution
        """

    def shutdown(self):
        """
        Shut down this session and close all connections.
        """

    def set_keyspace(self, keyspace):
        """
        Set the default keyspace for this session.

        Parameters:
        - keyspace (str): Keyspace name to use as default
        """

    @property
    def keyspace(self):
        """str: Current default keyspace for this session"""

    @property
    def cluster(self):
        """Cluster: The cluster this session is connected to"""

    @property
    def hosts(self):
        """set: Set of Host objects in the cluster"""

    @property
    def user_type_deserializers(self):
        """dict: User-defined type deserializers"""

    @property
    def encoder(self):
        """Encoder: Parameter encoder for this session"""

    @property
    def row_factory(self):
        """callable: Factory function for creating row objects from results"""

    @row_factory.setter
    def row_factory(self, factory):
        """Set the row factory for result processing"""

    @property
    def default_timeout(self):
        """float: Default timeout for queries executed by this session"""

    @default_timeout.setter
    def default_timeout(self, timeout):
        """Set the default timeout for queries"""

    @property
    def default_consistency_level(self):
        """int: Default consistency level for queries"""

    @default_consistency_level.setter 
    def default_consistency_level(self, consistency_level):
        """Set the default consistency level"""

    @property
    def default_serial_consistency_level(self):
        """int: Default serial consistency level for conditional queries"""

    @default_serial_consistency_level.setter
    def default_serial_consistency_level(self, serial_consistency_level):
        """Set the default serial consistency level"""

class ResponseFuture:
    def result(self, timeout=None):
        """
        Block until the query completes and return the result.

        Parameters:
        - timeout (float): Maximum time to wait for result

        Returns:
        ResultSet: Query results

        Raises:
        - Timeout: Operation timed out
        - Various query-specific exceptions
        """

    def get_query_trace(self, max_wait=2.0):
        """
        Get the query trace if tracing was enabled.

        Parameters:
        - max_wait (float): Maximum time to wait for trace data

        Returns:
        QueryTrace: Trace information for the executed query
        """

    def add_callback(self, fn, *args, **kwargs):
        """
        Add a callback function to be called when query completes successfully.

        Parameters:
        - fn (callable): Function to call with (result, *args, **kwargs)
        - args: Additional positional arguments for callback
        - kwargs: Additional keyword arguments for callback
        """

    def add_errback(self, fn, *args, **kwargs):
        """
        Add an error callback function to be called if query fails.

        Parameters:
        - fn (callable): Function to call with (exception, *args, **kwargs)
        - args: Additional positional arguments for callback
        - kwargs: Additional keyword arguments for callback
        """

    def add_callbacks(self, callback, errback, callback_args=(), callback_kwargs=None, errback_args=(), errback_kwargs=None):
        """
        Add both success and error callbacks.

        Parameters:
        - callback (callable): Success callback function
        - errback (callable): Error callback function
        - callback_args (tuple): Arguments for success callback
        - callback_kwargs (dict): Keyword arguments for success callback
        - errback_args (tuple): Arguments for error callback
        - errback_kwargs (dict): Keyword arguments for error callback
        """

    @property
    def query(self):
        """str or Statement: The query that was executed"""

    @property
    def session(self):
        """Session: The session used to execute the query"""

    @property
    def has_more_pages(self):
        """bool: Whether there are more pages of results available"""

class ResultSet:
    def __iter__(self):
        """Iterate over result rows"""

    def __len__(self):
        """Get the number of rows in current page"""

    def __getitem__(self, index):
        """Get a row by index"""

    @property
    def current_rows(self):
        """list: Rows in the current page"""

    @property
    def has_more_pages(self):
        """bool: Whether there are more pages available"""

    @property
    def response_future(self):
        """ResponseFuture: Future object used to fetch this result"""

    @property
    def column_names(self):
        """list: Names of columns in the result set"""

    @property
    def column_types(self):
        """list: CQL types of columns in the result set"""

class PagedResult:
    def __init__(self, future, session):
        """
        Initialize a paged result iterator.

        Parameters:
        - future (ResponseFuture): Initial response future
        - session (Session): Session for fetching additional pages
        """

    def __iter__(self):
        """Iterate over all rows across all pages"""

class Host:
    def __init__(self, address, datacenter=None, rack=None):
        """
        Represent a Cassandra host in the cluster.

        Parameters:
        - address (str): Host IP address or hostname
        - datacenter (str): Datacenter name
        - rack (str): Rack name
        """

    @property
    def address(self):
        """str: Host address"""

    @property
    def datacenter(self):
        """str: Datacenter name"""

    @property
    def rack(self):
        """str: Rack name"""

    @property
    def is_up(self):
        """bool: Whether the host is currently up"""

    @property
    def release_version(self):
        """str: Cassandra release version on this host"""

class HostConnectionPool:
    def __init__(self, host, host_distance, session):
        """
        Manage connections to a specific host.

        Parameters:
        - host (Host): Target host
        - host_distance (int): Distance category for this host
        - session (Session): Parent session
        """

    def borrow_connection(self, timeout):
        """
        Borrow a connection from the pool.

        Parameters:
        - timeout (float): Maximum time to wait for connection

        Returns:
        Connection: Available connection object
        """

    def return_connection(self, connection):
        """
        Return a connection to the pool.

        Parameters:
        - connection (Connection): Connection to return
        """

    @property
    def host(self):
        """Host: The host this pool connects to"""

    @property
    def is_shutdown(self):
        """bool: Whether this pool has been shut down"""

    @property
    def open_count(self):
        """int: Number of open connections in the pool"""

class NoHostAvailable(Exception):
    """No hosts are available for connection."""
    
    def __init__(self, message, errors):
        """
        Parameters:
        - message (str): Error message
        - errors (dict): Dict mapping Host objects to their connection errors
        """
    
    @property
    def errors(self):
        """dict: Connection errors by host"""

class QueryExhausted(Exception):
    """All query retries have been exhausted."""
    
    def __init__(self, message, last_host):
        """
        Parameters:
        - message (str): Error message  
        - last_host (Host): Last host that was tried
        """

class UserTypeDoesNotExist(Exception):
    """Referenced user-defined type does not exist."""
    
    def __init__(self, keyspace, user_type):
        """
        Parameters:
        - keyspace (str): Keyspace name
        - user_type (str): User-defined type name
        """

from cassandra.cluster import Cluster
from cassandra.auth import PlainTextAuthProvider
from cassandra.policies import DCAwareRoundRobinPolicy

# Setup authentication
auth_provider = PlainTextAuthProvider(username='cassandra', password='cassandra')

# Setup load balancing
load_balancing_policy = DCAwareRoundRobinPolicy(local_dc='datacenter1')

# Create cluster with custom configuration
cluster = Cluster(
    contact_points=['127.0.0.1', '127.0.0.2'],
    port=9042,
    auth_provider=auth_provider,
    load_balancing_policy=load_balancing_policy,
    protocol_version=4
)

# Connect and execute queries
session = cluster.connect()
session.set_keyspace('my_keyspace')

# Execute synchronous query
result = session.execute("SELECT * FROM users WHERE id = %s", [user_id])
for row in result:
    print(f"User: {row.name}")

# Execute asynchronous query
future = session.execute_async("SELECT * FROM users")
result = future.result()

# Clean up
cluster.shutdown()

# Prepare a statement for repeated execution
insert_stmt = session.prepare("""
    INSERT INTO users (id, name, email, created_at)
    VALUES (?, ?, ?, ?)
""")

# Execute with different parameters
import uuid
from datetime import datetime

session.execute(insert_stmt, [
    uuid.uuid4(),
    'Alice Smith', 
    'alice@example.com',
    datetime.now()
])

session.execute(insert_stmt, [
    uuid.uuid4(),
    'Bob Jones',
    'bob@example.com', 
    datetime.now()
])

def handle_success(result):
    print(f"Query succeeded with {len(result)} rows")
    for row in result:
        print(f"User: {row.name}")

def handle_error(exception):
    print(f"Query failed: {exception}")

# Execute with callbacks
future = session.execute_async("SELECT * FROM users")
future.add_callback(handle_success)
future.add_errback(handle_error)

# Or wait for result
try:
    result = future.result(timeout=10.0)
    print(f"Got {len(result)} rows")
except Exception as e:
    print(f"Query failed: {e}")