S3FS Integration¶

This section covers lightweight S3FS-based cursors, CSV readers, and data converters.

S3FS Cursors¶

class pyathena.s3fs.cursor.S3FSCursor(s3_staging_dir: str | None = None, schema_name: str | None = None, catalog_name: str | None = None, work_group: str | None = None, poll_interval: float = 1, encryption_option: str | None = None, kms_key: str | None = None, kill_on_interrupt: bool = True, result_reuse_enable: bool = False, result_reuse_minutes: int = 60, csv_reader: type[DefaultCSVReader] | type[AthenaCSVReader] | None = None, **kwargs)[source]¶

Cursor for reading CSV results via S3FileSystem without pandas/pyarrow.

This cursor uses Python’s standard csv module and PyAthena’s S3FileSystem to read query results from S3. It provides a lightweight alternative to pandas and arrow cursors when those dependencies are not needed.

The cursor is especially useful for:

Environments where pandas/pyarrow installation is not desired
Simple queries where advanced data processing is not required
Memory-constrained environments

description¶: Sequence of column descriptions for the last query.

rowcount¶: Number of rows affected by the last query (-1 for SELECT queries).

arraysize¶: Default number of rows to fetch with fetchmany().

Example

>>> from pyathena.s3fs.cursor import S3FSCursor
>>> cursor = connection.cursor(S3FSCursor)
>>> cursor.execute("SELECT * FROM my_table")
>>> rows = cursor.fetchall()  # Returns list of tuples
>>>
>>> # Iterate over results
>>> for row in cursor.execute("SELECT * FROM my_table"):
...     print(row)

# Use with SQLAlchemy >>> from sqlalchemy import create_engine >>> engine = create_engine(“awsathena+s3fs://…”)

__init__(s3_staging_dir: str | None = None, schema_name: str | None = None, catalog_name: str | None = None, work_group: str | None = None, poll_interval: float = 1, encryption_option: str | None = None, kms_key: str | None = None, kill_on_interrupt: bool = True, result_reuse_enable: bool = False, result_reuse_minutes: int = 60, csv_reader: type[DefaultCSVReader] | type[AthenaCSVReader] | None = None, **kwargs) → None[source]¶

Initialize an S3FSCursor.

Parameters:

s3_staging_dir – S3 location for query results.
schema_name – Default schema name.
catalog_name – Default catalog name.
work_group – Athena workgroup name.
poll_interval – Query status polling interval in seconds.
encryption_option – S3 encryption option (SSE_S3, SSE_KMS, CSE_KMS).
kms_key – KMS key ARN for encryption.
kill_on_interrupt – Cancel running query on keyboard interrupt.
result_reuse_enable – Enable Athena query result reuse.
result_reuse_minutes – Minutes to reuse cached results.
csv_reader – CSV reader class to use for parsing results. Use AthenaCSVReader (default) to distinguish between NULL (unquoted empty) and empty string (quoted empty “”). Use DefaultCSVReader for backward compatibility where empty strings are treated as NULL.
**kwargs – Additional connection parameters.

Example

>>> cursor = connection.cursor(S3FSCursor)
>>> cursor.execute("SELECT * FROM my_table")
>>>
>>> # Use DefaultCSVReader for backward compatibility
>>> from pyathena.s3fs.reader import DefaultCSVReader
>>> cursor = connection.cursor(S3FSCursor, csv_reader=DefaultCSVReader)

static get_default_converter(unload: bool = False) → DefaultS3FSTypeConverter[source]¶

Get the default type converter for S3FS cursor.

Parameters:: unload – Unused. S3FS cursor does not support UNLOAD operations.
Returns:: DefaultS3FSTypeConverter instance.

Execute a SQL query and return results.

Executes the SQL query on Amazon Athena and configures the result set for CSV-based output via S3FileSystem.

Parameters:

operation – SQL query string to execute.
parameters – Query parameters for parameterized queries.
work_group – Athena workgroup to use for this query.
s3_staging_dir – S3 location for query results.
cache_size – Number of queries to check for result caching.
cache_expiration_time – Cache expiration time in seconds.
result_reuse_enable – Enable Athena result reuse for this query.
result_reuse_minutes – Minutes to reuse cached results.
paramstyle – Parameter style (‘qmark’ or ‘pyformat’).
on_start_query_execution – Callback invoked with the query ID before execute() waits for the query: after the StartQueryExecution call, or after a reusable query ID is found through cache_size.
result_set_type_hints – Athena type signatures for complex-type columns, keyed by column name (case-insensitive) or zero-based column index.
options – Shared execution options as an ExecuteOptions instance. Individual keyword arguments take precedence over options fields.
**kwargs – Additional execution parameters.

Returns:

Self reference for method chaining.

Example

>>> cursor.execute("SELECT * FROM my_table WHERE id = %(id)s", {"id": 123})
>>> rows = cursor.fetchall()

DEFAULT_FETCH_SIZE: int = 1000¶

DEFAULT_RESULT_REUSE_MINUTES = 60¶

LIST_DATABASES_MAX_RESULTS = 50¶

LIST_QUERY_EXECUTIONS_MAX_RESULTS = 50¶

LIST_TABLE_METADATA_MAX_RESULTS = 50¶

property arraysize: int¶

The default number of rows per fetchmany() call.

execute() passes it to the new result set, so a change applies to the result sets of later executions. Setting it to zero or a negative value raises ProgrammingError.

Returns:: The default number of rows per fetchmany() call.

cancel() → None¶

Cancel the currently executing query.

Raises:: ProgrammingError – If no query is currently executing.

property catalog: str | None¶: The data catalog in the QueryExecutionContext of the query.

close() → None¶: Close the cursor and release associated resources.

property completion_date_time: datetime | None¶: The date and time when the query completed.

property connection: Connection[Any]¶: The connection that created this cursor.

property data_manifest_location: str | None¶: The S3 location of the data manifest that lists the files the query wrote.

property data_scanned_in_bytes: int | None¶: The number of bytes that the query scanned.

property database: str | None¶: The database in the QueryExecutionContext of the query.

property description: list[tuple[str, str, None, None, int, int, str]] | None¶: The DB API 2.0 column descriptions of the result set, or None without one.

property effective_engine_version: str | None¶: The Athena engine version that ran the query.

property encryption_option: str | None¶: The EncryptionOption of the query results, such as SSE_S3 or SSE_KMS.

property engine_execution_time_in_millis: int | None¶: The time in milliseconds that the query engine took to run the query.

property error_category: int | None¶

1 for system, 2 for user, 3 for other.

Type:: The ErrorCategory of the failure

property error_message: str | None¶: The ErrorMessage that describes the query failure.

property error_type: int | None¶: The ErrorType code of the query failure.

executemany(operation: str, seq_of_parameters: list[dict[str, Any] | list[str] | None], **kwargs) → None¶

Execute a SQL query multiple times with different parameters.

On success, rowcount is the sum of the affected row counts, or -1 if any execution has an unknown count. An empty parameter list sets it to 0. On failure, it is -1; earlier executions are not rolled back. Result sets are discarded.

On failure, query_id retains the current query ID when available. If parameter iteration fails, this can identify the last successful execution.

Parameters:

operation – SQL query string to execute.
seq_of_parameters – Sequence of parameter sets, one per execution.
**kwargs – Additional keyword arguments passed to each execute().

property execution_parameters: list[str]¶: The ExecutionParameters values of the query.

property expected_bucket_owner: str | None¶: The AWS account ID expected to own the S3 bucket of the query results.

fetchall() → list[tuple[Any | None, ...] | dict[Any, Any | None]]¶

Fetch all remaining rows from the result set.

Returns:: The remaining rows.
Raises:: ProgrammingError – If no result set is available.

fetchmany(size: int | None = None) → list[tuple[Any | None, ...] | dict[Any, Any | None]]¶

Fetch multiple rows from the result set.

Parameters:: size – Maximum number of rows to fetch. If None or not positive, arraysize is used.
Returns:: The fetched rows.
Raises:: ProgrammingError – If no result set is available.

fetchone() → tuple[Any | None, ...] | dict[Any, Any | None] | None¶

Fetch the next row of the result set.

Returns:: The next row (a tuple, or a dict for dict cursors), or None if no more rows.
Raises:: ProgrammingError – If no result set is available.

get_table_metadata(table_name: str, catalog_name: str | None = None, schema_name: str | None = None, logging_: bool = True) → AthenaTableMetadata¶

Get one table’s metadata.

In AwsDataCatalog and S3 Tables catalogs, a throttled request is answered from the AWS Glue Data Catalog; see glue_metadata_fallback.

Parameters:

table_name – The table name.
catalog_name – The catalog, or None for the cursor’s catalog.
schema_name – The database, or None for the cursor’s schema.
logging – Whether to log a failed request.

Returns:

The table’s metadata.

Raises:

OperationalError – If the request fails, including when the table does not exist.

property has_result_set: bool¶: Whether the cursor has a result set.

property kms_key: str | None¶: The KMS key used to encrypt the query results.

list_databases(catalog_name: str | None, max_results: int | None = None) → list[AthenaDatabase]¶

List the catalog’s databases.

In AwsDataCatalog and S3 Tables catalogs, a throttled request is answered from the AWS Glue Data Catalog; see glue_metadata_fallback.

Parameters:

catalog_name – The catalog, or None for the cursor’s catalog.
max_results – The page size of each request.

Returns:

The catalog’s databases.

Raises:

OperationalError – If the request fails.

list_table_metadata(catalog_name: str | None = None, schema_name: str | None = None, expression: str | None = None, max_results: int | None = None, logging_: bool = True) → list[AthenaTableMetadata]¶

List a database’s table metadata.

In AwsDataCatalog and S3 Tables catalogs, a throttled request is answered from the AWS Glue Data Catalog; see glue_metadata_fallback.

Parameters:

catalog_name – The catalog, or None for the cursor’s catalog.
schema_name – The database, or None for the cursor’s schema.
expression – A table name pattern.
max_results – The page size of each request.
logging – Whether to log a failed request.

Returns:

The metadata of the database’s tables.

Raises:

OperationalError – If the request fails.

property output_location: str | None¶: The S3 location of the query results.

property query: str | None¶: The SQL statement that the query execution ran.

property query_id: str | None¶

The query execution ID of the last execution.

With cache_size or cache_expiration_time, this can be the ID of a previous execution whose result is reused.

Returns:: The query execution ID, or None if there is none since the last reset.

property query_planning_time_in_millis: int | None¶: The time in milliseconds that Athena took to plan the query.

property query_queue_time_in_millis: int | None¶: The time in milliseconds that the query waited in the queue.

property result_reuse_enabled: bool | None¶: Whether reuse of previous query results by age is enabled for the query.

property result_reuse_minutes: int | None¶: The maximum age in minutes of a previous query result that Athena can reuse.

property result_set: AthenaResultSet | None¶

The result set of the last executed query.

Returns:: The result set, or None before a query succeeds or after a reset.

property retryable: bool | None¶: Whether Athena reports the query failure as retryable.

property reused_previous_result: bool | None¶: Whether Athena reused a previous query result instead of running the query.

property rowcount: int¶

Get the number of rows affected by the last operation.

For SELECT statements, this returns -1 as per DB API 2.0 specification. For DML operations (INSERT, UPDATE, DELETE) and CTAS, this returns the number of affected rows. After a successful executemany(), this is the sum across executions, or -1 if any count is unknown.

Returns:: The number of rows, or -1 if not applicable or unknown.

property rownumber: int | None¶

The zero-based index of the next row in the result set.

Returns:: The row index, or None if there is no result set or the index is unknown.

property s3_acl_option: str | None¶: The S3AclOption of the query results, such as BUCKET_OWNER_FULL_CONTROL.

property selected_engine_version: str | None¶: The Athena engine version selected to run the query.

property service_processing_time_in_millis: int | None¶: The time in milliseconds that Athena took to publish the query results.

setinputsizes(sizes)¶

Accept input sizes as DB API 2.0 requires, and ignore them.

Parameters:: sizes – Sequence of parameter types or sizes.

setoutputsize(size, column=None)¶

Accept a column buffer size as DB API 2.0 requires, and ignore it.

Parameters:

size – Buffer size for large columns.
column – Index of the column the size applies to, or None for all large columns.

property state: str | None¶: The state of the query execution, such as RUNNING or SUCCEEDED.

property state_change_reason: str | None¶: The StateChangeReason that gives further detail about the state.

property statement_type: str | None¶: The StatementType of the query, such as DDL, DML, or UTILITY.

property submission_date_time: datetime | None¶: The date and time when the query was submitted.

property substatement_type: str | None¶: The SubstatementType of the query, such as INSERT or MERGE.

property total_execution_time_in_millis: int | None¶: The total time in milliseconds that Athena took to run the query.

property work_group: str | None¶: The work group in which the query ran.

class pyathena.s3fs.async_cursor.AsyncS3FSCursor(s3_staging_dir: str | None = None, schema_name: str | None = None, catalog_name: str | None = None, work_group: str | None = None, poll_interval: float = 1, encryption_option: str | None = None, kms_key: str | None = None, kill_on_interrupt: bool = True, max_workers: int = 20, arraysize: int = 1000, result_reuse_enable: bool = False, result_reuse_minutes: int = 60, csv_reader: type[DefaultCSVReader] | type[AthenaCSVReader] | None = None, **kwargs)[source]¶

Asynchronous cursor that reads CSV results via S3FileSystem.

This cursor extends AsyncCursor to provide asynchronous query execution with results read via PyAthena’s S3FileSystem. It’s a lightweight alternative when pandas/pyarrow are not needed.

Features:

Asynchronous query execution with concurrent futures
Lightweight CSV parsing via pluggable readers
Uses PyAthena’s S3FileSystem for S3 access
No external dependencies beyond boto3
Memory-efficient streaming for large datasets

arraysize¶: Number of rows to fetch per batch (configurable).

Example

>>> from pyathena.s3fs.async_cursor import AsyncS3FSCursor
>>>
>>> cursor = connection.cursor(AsyncS3FSCursor)
>>> query_id, future = cursor.execute("SELECT * FROM my_table")
>>>
>>> # Get result when ready
>>> result_set = future.result()
>>> rows = result_set.fetchall()

Note

This cursor does not require pandas or pyarrow.

__init__(s3_staging_dir: str | None = None, schema_name: str | None = None, catalog_name: str | None = None, work_group: str | None = None, poll_interval: float = 1, encryption_option: str | None = None, kms_key: str | None = None, kill_on_interrupt: bool = True, max_workers: int = 20, arraysize: int = 1000, result_reuse_enable: bool = False, result_reuse_minutes: int = 60, csv_reader: type[DefaultCSVReader] | type[AthenaCSVReader] | None = None, **kwargs) → None[source]¶

Initialize an AsyncS3FSCursor.

Parameters:

s3_staging_dir – S3 location for query results.
schema_name – Default schema name.
catalog_name – Default catalog name.
work_group – Athena workgroup name.
poll_interval – Query status polling interval in seconds.
encryption_option – S3 encryption option (SSE_S3, SSE_KMS, CSE_KMS).
kms_key – KMS key ARN for encryption.
kill_on_interrupt – Cancel running query on keyboard interrupt.
max_workers – Maximum number of workers for concurrent execution.
arraysize – Number of rows to fetch per batch.
result_reuse_enable – Enable Athena query result reuse.
result_reuse_minutes – Minutes to reuse cached results.
csv_reader – CSV reader class to use for parsing results. Use AthenaCSVReader (default) to distinguish between NULL (unquoted empty) and empty string (quoted empty “”). Use DefaultCSVReader for backward compatibility where empty strings are treated as NULL.
**kwargs – Additional connection parameters.

Example

>>> cursor = connection.cursor(AsyncS3FSCursor)
>>> query_id, future = cursor.execute("SELECT * FROM my_table")

static get_default_converter(unload: bool = False) → DefaultS3FSTypeConverter[source]¶

Get the default type converter for S3FS cursor.

Parameters:: unload – Unused. S3FS cursor does not support UNLOAD operations.
Returns:: DefaultS3FSTypeConverter instance.

property arraysize: int¶: Get the number of rows to fetch at a time.

LIST_DATABASES_MAX_RESULTS = 50¶

LIST_QUERY_EXECUTIONS_MAX_RESULTS = 50¶

LIST_TABLE_METADATA_MAX_RESULTS = 50¶

cancel(query_id: str) → Future[None]¶

Cancel a running query asynchronously.

Submits a cancellation request for the specified query. The cancellation itself runs asynchronously in the background.

Parameters:: query_id – The Athena query execution ID to cancel.
Returns:: Future object that completes when the cancellation request finishes.

Example

>>> query_id, future = cursor.execute("SELECT * FROM huge_table")
>>> # Later, cancel the query
>>> cancel_future = cursor.cancel(query_id)
>>> cancel_future.result()  # Wait for cancellation to complete

close(wait: bool = False) → None¶: Close the cursor.

property connection: Connection[Any]¶: The connection that created this cursor.

description(query_id: str) → Future[list[tuple[str, str, None, None, int, int, str]] | None]¶

Get the column descriptions of a query’s result set asynchronously.

The future waits for the query to finish before it reads the result set.

Parameters:: query_id – The Athena query execution ID.
Returns:: Future object containing the DB API 2.0 column descriptions, or None.

Execute a SQL query asynchronously.

Submits the query to Athena and returns immediately with a query ID and a Future that will contain the result set when complete.

Parameters:

operation – SQL query string to execute.
parameters – Query parameters for parameterized queries.
work_group – Athena workgroup to use for this query.
s3_staging_dir – S3 location for query results.
cache_size – Number of queries to check for result caching.
cache_expiration_time – Cache expiration time in seconds.
result_reuse_enable – Enable Athena result reuse for this query.
result_reuse_minutes – Minutes to reuse cached results.
paramstyle – Parameter style (‘qmark’ or ‘pyformat’).
result_set_type_hints – Athena type signatures for complex-type columns, keyed by column name (case-insensitive) or zero-based column index.
options – Shared execution options as an ExecuteOptions instance. Individual keyword arguments take precedence over options fields.
**kwargs – Additional execution parameters.

Returns:

Tuple of (query_id, Future[AthenaS3FSResultSet]).

Example

>>> query_id, future = cursor.execute("SELECT * FROM my_table")
>>> result_set = future.result()
>>> rows = result_set.fetchall()

executemany(operation: str, seq_of_parameters: list[dict[str, Any] | list[str] | None], **kwargs) → None¶

Execute multiple queries asynchronously (not supported).

This method is not supported for asynchronous cursors because managing multiple concurrent queries would be complex and resource-intensive.

Parameters:

operation – SQL query string.
seq_of_parameters – Sequence of parameter sets.
**kwargs – Additional arguments.

Raises:

NotSupportedError – Always raised as this operation is not supported.

Note

For bulk operations, consider using execute() with parameterized queries or batch processing patterns instead.

get_table_metadata(table_name: str, catalog_name: str | None = None, schema_name: str | None = None, logging_: bool = True) → AthenaTableMetadata¶

Get one table’s metadata.

In AwsDataCatalog and S3 Tables catalogs, a throttled request is answered from the AWS Glue Data Catalog; see glue_metadata_fallback.

Parameters:

table_name – The table name.
catalog_name – The catalog, or None for the cursor’s catalog.
schema_name – The database, or None for the cursor’s schema.
logging – Whether to log a failed request.

Returns:

The table’s metadata.

Raises:

OperationalError – If the request fails, including when the table does not exist.

list_databases(catalog_name: str | None, max_results: int | None = None) → list[AthenaDatabase]¶

List the catalog’s databases.

In AwsDataCatalog and S3 Tables catalogs, a throttled request is answered from the AWS Glue Data Catalog; see glue_metadata_fallback.

Parameters:

catalog_name – The catalog, or None for the cursor’s catalog.
max_results – The page size of each request.

Returns:

The catalog’s databases.

Raises:

OperationalError – If the request fails.

List a database’s table metadata.

In AwsDataCatalog and S3 Tables catalogs, a throttled request is answered from the AWS Glue Data Catalog; see glue_metadata_fallback.

Parameters:

catalog_name – The catalog, or None for the cursor’s catalog.
schema_name – The database, or None for the cursor’s schema.
expression – A table name pattern.
max_results – The page size of each request.
logging – Whether to log a failed request.

Returns:

The metadata of the database’s tables.

Raises:

OperationalError – If the request fails.

poll(query_id: str) → Future[AthenaQueryExecution]¶

Poll for query completion asynchronously.

Waits for the query to complete (succeed, fail, or be cancelled) and returns the final execution status. This method blocks until completion but runs the polling in a background thread.

Parameters:: query_id – The Athena query execution ID to poll.
Returns:: Future object containing the final AthenaQueryExecution status.

Note

This method performs polling internally, so it will take time proportional to your query execution duration.

query_execution(query_id: str) → Future[AthenaQueryExecution]¶

Get query execution details asynchronously.

Retrieves the current execution status and metadata for a query. This is useful for monitoring query progress without blocking.

Parameters:: query_id – The Athena query execution ID.
Returns:: Future object containing AthenaQueryExecution with query details.

setinputsizes(sizes)¶

Accept input sizes as DB API 2.0 requires, and ignore them.

Parameters:: sizes – Sequence of parameter types or sizes.

setoutputsize(size, column=None)¶

Accept a column buffer size as DB API 2.0 requires, and ignore it.

Parameters:

size – Buffer size for large columns.
column – Index of the column the size applies to, or None for all large columns.

S3FS CSV Readers¶

S3FSCursor supports pluggable CSV reader implementations to control how NULL values and empty strings are handled when parsing Athena’s CSV output.

class pyathena.s3fs.reader.AthenaCSVReader(file_obj: Any, delimiter: str = ',')[source]¶

CSV reader that distinguishes between NULL and empty string.

This is the default reader for S3FSCursor.

Athena’s CSV output format distinguishes NULL values from empty strings: - NULL: unquoted empty field (e.g., ,, or ,field) - Empty string: quoted empty field (e.g., ,””, or ,””,field)

Python’s standard csv module parses both as empty strings, losing this distinction. This reader preserves the difference by returning None for NULL values and empty string for quoted empty values.

Example

>>> from io import StringIO
>>> reader = AthenaCSVReader(StringIO(',"",text'))
>>> list(reader)
[[None, '', 'text']]  # NULL and empty string are distinguished

Note

Use DefaultCSVReader if you need backward compatibility where both NULL and empty string are treated as empty string.

__init__(file_obj: Any, delimiter: str = ',') → None[source]¶

Initialize the reader.

Parameters:

file_obj – File-like object to read from.
delimiter – Field delimiter character.

__iter__() → AthenaCSVReader[source]¶: Iterate over rows in the CSV file.

__next__() → list[str | None][source]¶

Read and parse the next line.

Returns:: List of field values, with None for NULL and ‘’ for empty string.
Raises:: StopIteration – When end of file is reached or reader is closed.

close() → None[source]¶: Close the underlying file object.

__enter__() → AthenaCSVReader[source]¶: Enter context manager.

__exit__(exc_type: Any, exc_val: Any, exc_tb: Any) → None[source]¶: Exit context manager and close resources.

class pyathena.s3fs.reader.DefaultCSVReader(file_obj: Any, delimiter: str = ',')[source]¶

CSV reader using Python’s standard csv module.

This reader wraps Python’s standard csv.reader and treats empty fields as empty strings. It does not distinguish between NULL and empty strings in Athena’s CSV output - both become empty strings.

Use this reader when you need backward compatibility with the behavior where empty strings are treated the same as NULL values.

Example

>>> from io import StringIO
>>> reader = DefaultCSVReader(StringIO(',"",text'))
>>> list(reader)
[['', '', 'text']]  # Both NULL and empty string become ''

Note

The default reader for S3FSCursor is AthenaCSVReader, which distinguishes between NULL and empty string values.

__init__(file_obj: Any, delimiter: str = ',') → None[source]¶

Initialize the reader.

Parameters:

file_obj – File-like object to read from.
delimiter – Field delimiter character.

__iter__() → DefaultCSVReader[source]¶: Iterate over rows in the CSV file.

__next__() → list[str][source]¶

Read and parse the next line.

Returns:: List of field values as strings.
Raises:: StopIteration – When end of file is reached or reader is closed.

close() → None[source]¶: Close the underlying file object.

__enter__() → DefaultCSVReader[source]¶: Enter context manager.

__exit__(exc_type: Any, exc_val: Any, exc_tb: Any) → None[source]¶: Exit context manager and close resources.

S3FS Data Converters¶

class pyathena.s3fs.converter.DefaultS3FSTypeConverter[source]¶

Type converter for S3FS Cursor results.

This converter is specifically designed for the S3FSCursor and provides type conversion for CSV-based result files read via the S3 FileSystem. It converts Athena data types to Python types using the standard converter mappings.

The converter uses the same mappings as DefaultTypeConverter, providing consistent behavior with the standard Cursor while using the S3FileSystem for file access.

Example

>>> from pyathena.s3fs.converter import DefaultS3FSTypeConverter
>>> converter = DefaultS3FSTypeConverter()
>>>
>>> # Used automatically by S3FSCursor
>>> cursor = connection.cursor(S3FSCursor)
>>> # converter is applied automatically to results

Note

This converter is used by default in S3FSCursor. Most users don’t need to instantiate it directly.

__init__() → None[source]¶: Initialize the converter with the standard Athena conversion functions.

convert(type_: str, value: str | None, type_hint: str | None = None) → Any | None[source]¶

Convert a string value to the appropriate Python type.

Looks up the converter function for the given Athena type and applies it to the value. If the value is None, returns None without conversion.

Parameters:

type – The Athena data type name (e.g., “integer”, “varchar”, “date”).
value – The string value to convert, or None.
type_hint – Optional Athena DDL type signature for precise complex type conversion (e.g., “array(varchar)”).

Returns:

The converted Python value, or None if the input value was None.

S3FS Result Set¶

class pyathena.s3fs.result_set.AthenaS3FSResultSet(connection: Connection[Any], converter: Converter, query_execution: AthenaQueryExecution, arraysize: int, retry_config: RetryConfig, block_size: int | None = None, csv_reader: CSVReaderType | None = None, filesystem_class: type[AbstractFileSystem] | None = None, result_set_type_hints: dict[str | int, str] | None = None, **kwargs)[source]¶

Result set that reads CSV results via S3FileSystem without pandas/pyarrow.

This result set uses PyAthena’s S3FileSystem to read query results from S3. It provides a lightweight alternative to pandas and arrow cursors when those dependencies are not needed.

Features:

Lightweight CSV parsing via pluggable readers
Uses PyAthena’s S3FileSystem for S3 access
No external dependencies beyond boto3
Memory-efficient streaming for large datasets

DEFAULT_BLOCK_SIZE¶: Default block size for S3 operations (128MB).

Example

>>> # Used automatically by S3FSCursor
>>> cursor = connection.cursor(S3FSCursor)
>>> cursor.execute("SELECT * FROM my_table")
>>>
>>> # Fetch results
>>> rows = cursor.fetchall()

Note

This class is used internally by S3FSCursor and typically not instantiated directly by users.

DEFAULT_FETCH_SIZE: int = 1000¶

DEFAULT_BLOCK_SIZE = 134217728¶

__init__(connection: Connection[Any], converter: Converter, query_execution: AthenaQueryExecution, arraysize: int, retry_config: RetryConfig, block_size: int | None = None, csv_reader: CSVReaderType | None = None, filesystem_class: type[AbstractFileSystem] | None = None, result_set_type_hints: dict[str | int, str] | None = None, **kwargs) → None[source]¶

Initialize the result set and prepare to read the query results.

Parameters:

connection – The connection that ran the query.
converter – The converter for result values.
query_execution – The query execution whose results to read.
arraysize – The number of rows read from the CSV results per fetch and the default fetchmany() size.
retry_config – The retry configuration for API calls.
block_size – The default block size in bytes for the filesystem. If not set, DEFAULT_BLOCK_SIZE is used.
csv_reader – The CSV reader class for the results. If None, AthenaCSVReader is used.
filesystem_class – The filesystem class for reading the results. If None, PyAthena’s S3FileSystem is used.
result_set_type_hints – Athena type signatures for complex-type columns, keyed by column name (case-insensitive) or zero-based column index.
**kwargs – Additional keyword arguments, which are ignored.

Raises:

ProgrammingError – If query_execution is not given.
OperationalError – If reading the query results fails.

fetchone() → tuple[Any | None, ...] | dict[Any, Any | None] | None[source]¶

Fetch the next row of the result set.

Returns:: A tuple representing the next row, or None if no more rows.

close() → None[source]¶: Close the result set and release resources.

DEFAULT_RESULT_REUSE_MINUTES = 60¶

property arraysize: int¶: The default number of rows per fetchmany() call.

property catalog: str | None¶: The data catalog in the QueryExecutionContext of the query.

property completion_date_time: datetime | None¶: The date and time when the query completed.

property connection: Connection[Any]¶: The connection of the result set; raises ProgrammingError if closed.

property data_manifest_location: str | None¶: The S3 location of the data manifest that lists the files the query wrote.

property data_scanned_in_bytes: int | None¶: The number of bytes that the query scanned.

property database: str | None¶: The database in the QueryExecutionContext of the query.

property description: list[tuple[str, str, None, None, int, int, str]] | None¶

The DB API 2.0 column descriptions.

None without result metadata, or for INSERT, UPDATE, DELETE, and MERGE.

property effective_engine_version: str | None¶: The Athena engine version that ran the query.

property encryption_option: str | None¶: The EncryptionOption of the query results, such as SSE_S3 or SSE_KMS.

property engine_execution_time_in_millis: int | None¶: The time in milliseconds that the query engine took to run the query.

property error_category: int | None¶

1 for system, 2 for user, 3 for other.

Type:: The ErrorCategory of the failure

property error_message: str | None¶: The ErrorMessage that describes the query failure.

property error_type: int | None¶: The ErrorType code of the query failure.

property execution_parameters: list[str]¶: The ExecutionParameters values of the query.

property expected_bucket_owner: str | None¶: The AWS account ID expected to own the S3 bucket of the query results.

fetchall() → list[tuple[Any | None, ...] | dict[Any, Any | None]]¶

Fetch all remaining rows of the query result.

Returns:: The remaining rows.

fetchmany(size: int | None = None) → list[tuple[Any | None, ...] | dict[Any, Any | None]]¶

Fetch the next set of rows of the query result.

Parameters:: size – Maximum number of rows to fetch. If None or not positive, arraysize is used.
Returns:: The rows, fewer than size when the result is exhausted.

property is_closed: bool¶: Whether the result set is closed.

property is_unload: bool¶

Check if the query is an UNLOAD statement.

Returns:: True if the query is an UNLOAD statement, False otherwise.

property kms_key: str | None¶: The KMS key used to encrypt the query results.

property output_location: str | None¶: The S3 location of the query results.

property query: str | None¶: The SQL statement that the query execution ran.

property query_id: str | None¶: The ID of the query execution.

property query_planning_time_in_millis: int | None¶: The time in milliseconds that Athena took to plan the query.

property query_queue_time_in_millis: int | None¶: The time in milliseconds that the query waited in the queue.

property result_reuse_enabled: bool | None¶: Whether reuse of previous query results by age is enabled for the query.

property result_reuse_minutes: int | None¶: The maximum age in minutes of a previous query result that Athena can reuse.

property retryable: bool | None¶: Whether Athena reports the query failure as retryable.

property reused_previous_result: bool | None¶: Whether Athena reused a previous query result instead of running the query.

property rowcount: int¶: The number of rows affected by the last operation, or -1 if it is unknown.

property rownumber: int | None¶: The zero-based index of the next row, or None if it is unknown.

property s3_acl_option: str | None¶: The S3AclOption of the query results, such as BUCKET_OWNER_FULL_CONTROL.

property selected_engine_version: str | None¶: The Athena engine version selected to run the query.

property service_processing_time_in_millis: int | None¶: The time in milliseconds that Athena took to publish the query results.

property state: str | None¶: The state of the query execution, such as RUNNING or SUCCEEDED.

property state_change_reason: str | None¶: The StateChangeReason that gives further detail about the state.

property statement_type: str | None¶: The StatementType of the query, such as DDL, DML, or UTILITY.

property submission_date_time: datetime | None¶: The date and time when the query was submitted.

property substatement_type: str | None¶: The SubstatementType of the query, such as INSERT or MERGE.

property total_execution_time_in_millis: int | None¶: The total time in milliseconds that Athena took to run the query.

property work_group: str | None¶: The work group in which the query ran.