pyarrow.CompressedOutputStream#

class pyarrow.CompressedOutputStream(stream, unicode compression)#

Bases: pyarrow.lib.NativeFile

An output stream wrapper which compresses data on the fly.

Parameters

streamstr, path, pyarrow.NativeFile, or file-like object: Input stream object to wrap with the compression.
compressionstr: The compression type (“bz2”, “brotli”, “gzip”, “lz4” or “zstd”).

__init__(*args, **kwargs)#

Methods

`__init__`(args, *kwargs)
`close`(self)
`download`(self, stream_or_path[, buffer_size])	Read this file completely to a local path or destination stream.
`fileno`(self)	NOT IMPLEMENTED
`flush`(self)	Flush the stream, if applicable.
`isatty`(self)
`metadata`(self)	Return file metadata
`read`(self[, nbytes])	Read indicated number of bytes from file, or read all remaining bytes if no argument passed
`read1`(self[, nbytes])	Read and return up to n bytes.
`read_at`(self, nbytes, offset)	Read indicated number of bytes at offset from the file
`read_buffer`(self[, nbytes])
`readable`(self)
`readall`(self)
`readinto`(self, b)	Read into the supplied buffer
`readline`(self[, size])	NOT IMPLEMENTED.
`readlines`(self[, hint])	NOT IMPLEMENTED.
`seek`(self, int64_t position, int whence=0)	Change current file stream position
`seekable`(self)
`size`(self)	Return file size
`tell`(self)	Return current stream position
`truncate`(self)	NOT IMPLEMENTED
`upload`(self, stream[, buffer_size])	Write from a source stream to this file.
`writable`(self)
`write`(self, data)	Write byte from any object implementing buffer protocol (bytes, bytearray, ndarray, pyarrow.Buffer)
`writelines`(self, lines)

Attributes

`closed`
`mode`	The file mode.

close(self)#

closed#

download(self, stream_or_path, buffer_size=None)#

Read this file completely to a local path or destination stream.

This method first seeks to the beginning of the file.

Parameters

stream_or_pathstr or file-like object: If a string, a local file path to write to; otherwise, should be a writable stream.
buffer_sizeint, optional: The buffer size to use for data transfers.

fileno(self)#: NOT IMPLEMENTED

flush(self)#

Flush the stream, if applicable.

An error is raised if stream is not writable.

isatty(self)#

metadata(self)#: Return file metadata

mode#

The file mode. Currently instances of NativeFile may support:

rb: binary read
wb: binary write
rb+: binary read and write

read(self, nbytes=None)#

Read indicated number of bytes from file, or read all remaining bytes if no argument passed

Parameters

nbytesint, default None

Returns

databytes

read1(self, nbytes=None)#

Read and return up to n bytes.

Alias for read, needed to match the BufferedIOBase interface.

Parameters

nbytesint: The maximum number of bytes to read.

read_at(self, nbytes, offset)#

Read indicated number of bytes at offset from the file

Parameters

nbytesint
offsetint

Returns

databytes

read_buffer(self, nbytes=None)#

readable(self)#

readall(self)#

readinto(self, b)#

Read into the supplied buffer

Parameters

bbuffer-like object: A writable buffer object (such as a bytearray).

Returns

writtenint: number of bytes written

readline(self, size=None)#

NOT IMPLEMENTED. Read and return a line of bytes from the file.

If size is specified, read at most size bytes.

Line terminator is always b”n”.

Parameters

sizeint: maximum number of bytes read

readlines(self, hint=None)#

NOT IMPLEMENTED. Read lines of the file

Parameters

hintint: maximum number of bytes read until we stop

seek(self, int64_t position, int whence=0)#

Change current file stream position

Parameters

positionint: Byte offset, interpreted relative to value of whence argument
whenceint, default 0: Point of reference for seek offset

Returns

int: The new absolute stream position.

Notes

Values of whence: * 0 – start of stream (the default); offset should be zero or positive * 1 – current stream position; offset may be negative * 2 – end of stream; offset is usually negative

seekable(self)#

size(self)#: Return file size

tell(self)#: Return current stream position

truncate(self)#: NOT IMPLEMENTED

upload(self, stream, buffer_size=None)#

Write from a source stream to this file.

Parameters

streamfile-like object: Source stream to pipe to this file.
buffer_sizeint, optional: The buffer size to use for data transfers.

writable(self)#

write(self, data)#

Write byte from any object implementing buffer protocol (bytes, bytearray, ndarray, pyarrow.Buffer)

Parameters

databytes-like object or exporter of buffer protocol

Returns

int: nbytes: number of bytes written

writelines(self, lines)#

pyarrow.CompressedInputStream

Tables and Tensors