Polars

https://www.pola.rs

Warning

This backend is experimental and is subject to backwards incompatible changes.

Install

Install Ibis and dependencies for the Polars backend:

pip

Install with the polars extra:

pip install 'ibis-framework[polars]'

And connect:

import ibis

con = ibis.polars.connect()

1

Adjust connection parameters as needed.

conda

Install for Polars:

conda install -c conda-forge ibis-polars

And connect:

import ibis

con = ibis.polars.connect()

1

Adjust connection parameters as needed.

mamba

Install for Polars:

mamba install -c conda-forge ibis-polars

And connect:

import ibis

con = ibis.polars.connect()

1

Adjust connection parameters as needed.

Connect

ibis.polars.connect

con = ibis.polars.connect()

Note

ibis.polars.connect is a thin wrapper around ibis.backends.polars.Backend.do_connect.

Connection Parameters

do_connect

do_connect(self, tables=None)

Construct a client from a dictionary of polars LazyFrames and/or DataFrames.

Parameters

Name	Type	Description	Default
tables	MutableMapping[str, pl.LazyFrame | pl.DataFrame] | None	An optional mapping of string table names to polars LazyFrames.	None

polars.Backend

compile

compile(self, expr, params=None, **_)

Compile an expression.

create_table

create_table(self, name, obj=None, *, schema=None, database=None, temp=None, overwrite=False)

Create a new table.

Parameters

Name	Type	Description	Default
name	str	Name of the new table.	required
obj	pd.DataFrame | pa.Table | ir.Table | None	An Ibis table expression or pandas table that will be used to extract the schema and the data of the new table. If not provided, schema must be given.	None
schema	ibis.Schema | None	The schema for the new table. Only one of schema or obj can be provided.	None
database	str | None	Name of the database where the table will be created, if not the default.	None
temp	bool	Whether a table is temporary or not	False
overwrite	bool	Whether to clobber existing data	False

Returns

Type	Description
Table	The table that was created.

create_view

create_view(self, *_, **__)

Create a new view from an expression.

Parameters

Name	Type	Description	Default
name	str	Name of the new view.	required
obj	ir.Table	An Ibis table expression that will be used to create the view.	required
database	str | None	Name of the database where the view will be created, if not provided the database’s default is used.	None
overwrite	bool	Whether to clobber an existing view with the same name	False

Returns

Type	Description
Table	The view that was created.

database

database(self, name=None)

Return a Database object for the name database.

Parameters

Name	Type	Description	Default
name	str | None	Name of the database to return the object for.	None

Returns

Type	Description
Database	A database object for the specified database.

drop_table

drop_table(self, *_, **__)

Drop a table.

Parameters

Name	Type	Description	Default
name	str	Name of the table to drop.	required
database	str | None	Name of the database where the table exists, if not the default.	None
force	bool	If False, an exception is raised if the table does not exist.	False

drop_view

drop_view(self, *_, **__)

Drop a view.

Parameters

Name	Type	Description	Default
name	str	Name of the view to drop.	required
database	str | None	Name of the database where the view exists, if not the default.	None
force	bool	If False, an exception is raised if the view does not exist.	False

execute

execute(self, expr, params=None, limit=None, **kwargs)

Execute an expression.

get_schema

get_schema(self, table_name, database=None)

has_operation

has_operation(cls, operation)

Return whether the backend implements support for operation.

Parameters

Name	Type	Description	Default
operation	type[ops.Value]	A class corresponding to an operation.	required

Returns

Type	Description
bool	Whether the backend implements the operation.

Examples

>>> import ibis
>>> import ibis.expr.operations as ops
>>> ibis.sqlite.has_operation(ops.ArrayIndex)
False
>>> ibis.postgres.has_operation(ops.ArrayIndex)
True

list_tables

list_tables(self, like=None, database=None)

Return the list of table names in the current database.

For some backends, the tables may be files in a directory, or other equivalent entities in a SQL database.

Parameters

Name	Type	Description	Default
like	str | None	A pattern in Python’s regex format.	None
database	str | None	The database from which to list tables. If not provided, the current database is used.	None

Returns

Type	Description
list[str]	The list of the table names that match the pattern like.

read_csv

read_csv(self, path, table_name=None, **kwargs)

Register a CSV file as a table.

Parameters

Name	Type	Description	Default
path	str | Path	The data source. A string or Path to the CSV file.	required
table_name	str | None	An optional name to use for the created table. This defaults to a sequentially generated name.	None
**kwargs	Any	Additional keyword arguments passed to Polars loading function. See https://pola-rs.github.io/polars/py-polars/html/reference/api/polars.scan_csv.html for more information.	{}

Returns

Type	Description
ir.Table	The just-registered table

read_delta

read_delta(self, path, table_name=None, **kwargs)

Register a Delta Lake as a table in the current database.

Parameters

Name	Type	Description	Default
path	str | Path	The data source(s). Path to a Delta Lake table directory.	required
table_name	str | None	An optional name to use for the created table. This defaults to a sequentially generated name.	None
**kwargs	Any	Additional keyword arguments passed to Polars loading function. See https://pola-rs.github.io/polars/py-polars/html/reference/api/polars.scan_delta.html for more information.	{}

Returns

Type	Description
ir.Table	The just-registered table

read_json

read_json(self, path, table_name=None, **kwargs)

Register a JSON file as a table.

Parameters

Name	Type	Description	Default
path	str | Path	A string or Path to a JSON file; globs are supported	required
table_name	str | None	An optional name to use for the created table. This defaults to a sequentially generated name.	None
**kwargs	Any	Additional keyword arguments passed to Polars loading function. See https://pola-rs.github.io/polars/py-polars/html/reference/api/polars.scan_ndjson.html for more information.	{}

Returns

Type	Description
ir.Table	The just-registered table

read_pandas

read_pandas(self, source, table_name=None, **kwargs)

Register a Pandas DataFrame or pyarrow Table a table in the current database.

Parameters

Name	Type	Description	Default
source	pd.DataFrame	The data source.	required
table_name	str | None	An optional name to use for the created table. This defaults to a sequentially generated name.	None
**kwargs	Any	Additional keyword arguments passed to Polars loading function. See https://pola-rs.github.io/polars/py-polars/html/reference/api/polars.from_pandas.html for more information.	{}

Returns

Type	Description
ir.Table	The just-registered table

read_parquet

read_parquet(self, path, table_name=None, **kwargs)

Register a parquet file as a table in the current database.

Parameters

Name	Type	Description	Default
path	str | Path | Iterable[str]	The data source(s). May be a path to a file, an iterable of files, or directory of parquet files.	required
table_name	str | None	An optional name to use for the created table. This defaults to a sequentially generated name.	None
**kwargs	Any	Additional keyword arguments passed to Polars loading function. See https://pola-rs.github.io/polars/py-polars/html/reference/api/polars.scan_parquet.html for more information (if loading a single file or glob; when loading multiple files polars’ scan_pyarrow_dataset method is used instead).	{}

Returns

Type	Description
ir.Table	The just-registered table

register

register(self, source, table_name=None, **kwargs)

Register a data source as a table in the current database.

Parameters

Name	Type	Description	Default
source	str | Path | Any	The data source(s). May be a path to a file, a parquet directory, or a pandas dataframe.	required
table_name	str | None	An optional name to use for the created table. This defaults to a sequentially generated name.	None
**kwargs	Any	Additional keyword arguments passed to Polars loading functions for CSV or parquet. See https://pola-rs.github.io/polars/py-polars/html/reference/api/polars.scan_csv.html and https://pola-rs.github.io/polars/py-polars/html/reference/api/polars.scan_parquet.html for more information	{}

Returns

Type	Description
ir.Table	The just-registered table

sql

sql(self, query, schema=None, dialect=None)

table

table(self, name, _schema=None)

Construct a table expression.

Parameters

Name	Type	Description	Default
name	str	Table name	required
database	str | None	Database name	None

Returns

Type	Description
Table	Table expression

to_pyarrow

to_pyarrow(self, expr, params=None, limit=None, **kwargs)

Execute expression and return results in as a pyarrow table.

This method is eager and will execute the associated expression immediately.

Parameters

Name	Type	Description	Default
expr	ir.Expr	Ibis expression to export to pyarrow	required
params	Mapping[ir.Scalar, Any] | None	Mapping of scalar parameter expressions to value.	None
limit	int | str | None	An integer to effect a specific row limit. A value of None means “no limit”. The default is in ibis/config.py.	None
kwargs	Any	Keyword arguments	{}

Returns

Type	Description
Table	A pyarrow table holding the results of the executed expression.

to_pyarrow_batches

to_pyarrow_batches(self, expr, *, params=None, limit=None, chunk_size=1000000, **kwargs)

Execute expression and return a RecordBatchReader.

This method is eager and will execute the associated expression immediately.

Parameters

Name	Type	Description	Default
expr	ir.Expr	Ibis expression to export to pyarrow	required
limit	int | str | None	An integer to effect a specific row limit. A value of None means “no limit”. The default is in ibis/config.py.	None
params	Mapping[ir.Scalar, Any] | None	Mapping of scalar parameter expressions to value.	None
chunk_size	int	Maximum number of rows in each returned record batch.	1000000
kwargs	Any	Keyword arguments	{}

Returns

Type	Description
results	RecordBatchReader