pyarrow.NativeFile¶
- class pyarrow.NativeFile¶
Bases:
pyarrow.lib._WeakrefableThe base class for all Arrow streams.
Streams are either readable, writable, or both. They optionally support seeking.
While this class exposes methods to read or write data from Python, the primary intent of using a Arrow stream is to pass it to other Arrow facilities that will make use of it, such as Arrow IPC routines.
Be aware that there are subtle differences with regular Python files, e.g. destroying a writable Arrow stream without closing it explicitly will not flush any pending data.
- __init__(*args, **kwargs)¶
Methods
__init__(*args, **kwargs)close(self)download(self, stream_or_path[, buffer_size])Read file completely to local path (rather than reading completely into memory).
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])Pipe file-like object to file
writable(self)write(self, data)Write byte from any object implementing buffer protocol (bytes, bytearray, ndarray, pyarrow.Buffer)
writelines(self, lines)Attributes
The file mode.
- close(self)¶
- closed¶
- download(self, stream_or_path, buffer_size=None)¶
Read file completely to local path (rather than reading completely into memory). First seeks to the beginning of the file.
- 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
- read1(self, nbytes=None)¶
Read and return up to n bytes.
Alias for read, needed to match the IOBase interface.
- read_at(self, nbytes, offset)¶
Read indicated number of bytes at offset from the file
- read_buffer(self, nbytes=None)¶
- readable(self)¶
- readall(self)¶
- readinto(self, b)¶
Read into the supplied buffer
- Parameters
- b: any python object supporting buffer interface
- Returns
intnumber 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”.
- readlines(self, hint=None)¶
NOT IMPLEMENTED. Read lines of the file
- Parameters
- hint: int maximum number of bytes read until we stop
- seek(self, int64_t position, int whence=0)¶
Change current file stream position
- Parameters
- Returns
intThe 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)¶
Pipe file-like object to file
- writable(self)¶
- write(self, data)¶
Write byte from any object implementing buffer protocol (bytes, bytearray, ndarray, pyarrow.Buffer)
- Parameters
- databytes-like object or
exporterof buffer protocol
- databytes-like object or
- Returns
intnbytes: number of bytes written
- writelines(self, lines)¶