Input/output

CSV

read_csv(source, *[, has_header, columns, ...])	Read a CSV file into a DataFrame.
read_csv_batched(source, *[, has_header, ...])	Read a CSV file in batches.
scan_csv(source, *[, has_header, separator, ...])	Lazily read from a CSV file or multiple files via glob patterns.
DataFrame.write_csv()	Write to comma-separated values (CSV) file.
LazyFrame.sink_csv(path, *[, include_bom, ...])	Evaluate the query in streaming mode and write to a CSV file.

Feather/ IPC

read_ipc(source, *[, columns, n_rows, ...])	Read into a DataFrame from Arrow IPC (Feather v2) file.
read_ipc_stream(source, *[, columns, ...])	Read into a DataFrame from Arrow IPC record batch stream.
scan_ipc(source, *[, n_rows, cache, ...])	Lazily read from an Arrow IPC (Feather v2) file or multiple files via glob patterns.
read_ipc_schema(source)	Get the schema of an IPC file without reading data.
DataFrame.write_ipc()	Write to Arrow IPC binary stream or Feather file.
DataFrame.write_ipc_stream()	Write to Arrow IPC record batch stream.
LazyFrame.sink_ipc(path, *[, compression, ...])	Evaluate the query in streaming mode and write to an IPC file.

Parquet

read_parquet(source, *[, columns, n_rows, ...])	Read into a DataFrame from a parquet file.
scan_parquet(source, *[, n_rows, cache, ...])	Lazily read from a local or cloud-hosted parquet file (or files).
read_parquet_schema(source)	Get the schema of a Parquet file without reading data.
DataFrame.write_parquet(file, *[, ...])	Write to Apache Parquet file.
LazyFrame.sink_parquet(path, *[, ...])	Evaluate the query in streaming mode and write to a Parquet file.

Database

read_database()	Read the results of a SQL query into a DataFrame, given a connection object.
read_database_uri(query, uri, *[, ...])	Read the results of a SQL query into a DataFrame, given a URI.
DataFrame.write_database(table_name, ...[, ...])	Write a polars frame to a database.

JSON

read_json(source, *[, infer_schema_length, ...])	Read into a DataFrame from a JSON file.
read_ndjson(source, *[, schema, ...])	Read into a DataFrame from a newline delimited JSON file.
scan_ndjson(source, *[, ...])	Lazily read from a newline delimited JSON file or multiple files via glob patterns.
DataFrame.write_json()	Serialize to JSON representation.
DataFrame.write_ndjson()	Serialize to newline delimited JSON representation.

AVRO

read_avro(source, *[, columns, n_rows])	Read into a DataFrame from Apache Avro format.
DataFrame.write_avro(file[, compression, name])	Write to Apache Avro file.

Spreadsheet

read_excel()	Read Excel (XLSX) spreadsheet data into a DataFrame.
read_ods()	Read OpenOffice (ODS) spreadsheet data into a DataFrame.
DataFrame.write_excel([workbook, worksheet, ...])	Write frame data to a table in an Excel workbook/worksheet.

Apache Iceberg

scan_iceberg(source, *[, storage_options])

Lazily read from an Apache Iceberg table.

Delta Lake

scan_delta(source, *[, version, ...])	Lazily read from a Delta lake table.
read_delta(source, *[, version, columns, ...])	Reads into a DataFrame from a Delta lake table.
DataFrame.write_delta(target, *[, mode, ...])	Write DataFrame as delta table.

Datasets

Connect to pyarrow datasets.

scan_pyarrow_dataset(source, *[, ...])

Scan a pyarrow dataset.

BatchedCsvReader

This reader comes available by calling pl.read_csv_batched.

BatchedCsvReader.next_batches(n)

Read n batches from the reader.