pyarrow.csv.CSVStreamingReader

class pyarrow.csv.CSVStreamingReader

Bases: RecordBatchReader

An object that reads record batches incrementally from a CSV file.

Should not be instantiated directly by user code.

__init__(*args, **kwargs)

Methods

__init__(*args, **kwargs)
cast(self, target_schema)	Wrap this reader with one that casts each batch lazily as it is pulled.
close(self)	Release any resources associated with the reader.
from_batches(Schema schema, batches)	Create RecordBatchReader from an iterable of batches.
from_stream(data[, schema])	Create RecordBatchReader from a Arrow-compatible stream object.
iter_batches_with_custom_metadata(self)	Iterate over record batches from the stream along with their custom metadata.
read_all(self)	Read all record batches as a pyarrow.Table.
read_next_batch(self)	Read next RecordBatch from the stream.
read_next_batch_with_custom_metadata(self)	Read next RecordBatch from the stream along with its custom metadata.
read_pandas(self, **options)	Read contents of stream to a pandas.DataFrame.

Attributes

schema

cast(self, target_schema)

Wrap this reader with one that casts each batch lazily as it is pulled. Currently only a safe cast to target_schema is implemented.

Parameters:

target_schemaSchema

Schema to cast to, the names and order of fields must match.

Returns:

RecordBatchReader

close(self)

Release any resources associated with the reader.

static from_batches(Schema schema, batches)

Create RecordBatchReader from an iterable of batches.

Parameters:

schemaSchema

The shared schema of the record batches

batchesIterable[RecordBatch]

The batches that this reader will return.

Returns:

readerRecordBatchReader

static from_stream(data, schema=None)

Create RecordBatchReader from a Arrow-compatible stream object.

This accepts objects implementing the Arrow PyCapsule Protocol for streams, i.e. objects that have a __arrow_c_stream__ method.

Parameters:

dataArrow-compatible stream object

Any object that implements the Arrow PyCapsule Protocol for streams.

schemaSchema, default None

The schema to which the stream should be casted, if supported by the stream object.

Returns:

RecordBatchReader

iter_batches_with_custom_metadata(self)

Iterate over record batches from the stream along with their custom metadata.

Yields:

RecordBatchWithMetadata

read_all(self)

Read all record batches as a pyarrow.Table.

Returns:

Table

read_next_batch(self)

Read next RecordBatch from the stream.

Returns:

RecordBatch

Raises:

StopIteration:

At end of stream.

read_next_batch_with_custom_metadata(self)

Read next RecordBatch from the stream along with its custom metadata.

Returns:

batchRecordBatch

custom_metadataKeyValueMetadata

Raises:

StopIteration:

At end of stream.

read_pandas(self, **options)

Read contents of stream to a pandas.DataFrame.

Read all record batches as a pyarrow.Table then convert it to a pandas.DataFrame using Table.to_pandas.

Parameters:

**options

Arguments to forward to Table.to_pandas().

Returns:

dfpandas.DataFrame

schema