openers

Context manager openers for various fileobject types

Fileish(*args, **kwargs)
ImageOpener(fileish, *args, **kwargs)	Opener-type class to collect extra compressed extensions
Opener(fileish, *args, **kwargs)	Class to accept, maybe open, and context-manage file-likes / filenames

Fileish

class nibabel.openers.Fileish(*args, **kwargs)

Bases: Protocol

__init__(*args, **kwargs)

read(size: int = -1, /) → bytes

write(b: bytes, /) → int | None

ImageOpener

class nibabel.openers.ImageOpener(fileish: str | IOBase, *args, **kwargs)

Bases: Opener

Opener-type class to collect extra compressed extensions

A trivial sub-class of opener to which image classes can add extra extensions with custom openers, such as compressed openers.

To add an extension, add a line to the class definition (not __init__):

ImageOpener.compress_ext_map[ext] = func_def

ext is a file extension beginning with ‘.’ and should be included in the image class’s valid_exts tuple.

func_def is a (function, (args,)) tuple, where function accepts a filename as the first parameter, and `args defines the other arguments that function accepts. These arguments must be any (unordered) subset of mode, compresslevel, and buffering.

__init__(fileish: str | IOBase, *args, **kwargs)

compress_ext_map = {'.bz2': (<class 'bz2.BZ2File'>, ('mode', 'buffering', 'compresslevel')), '.gz': (<function gzip_open>, ('mode', 'compresslevel', 'mtime', 'keep_open')), '.mgz': (<function gzip_open>, ('mode', 'compresslevel', 'mtime', 'keep_open')), '.zst': (<function zstd_open>, ('mode', 'level', 'option', 'zstd_dict')), None: (<built-in function open>, ('mode', 'buffering'))}

Opener

class nibabel.openers.Opener(fileish: str | IOBase, *args, **kwargs)

Bases: object

Class to accept, maybe open, and context-manage file-likes / filenames

Provides context manager to close files that the constructor opened for you.

Parameters:

fileishstr or file-like

if str, then open with suitable opening method. If file-like, accept as is

*argspositional arguments

passed to opening method when fileish is str. mode, if not specified, is rb. compresslevel, if relevant, and not specified, is set from class variable default_compresslevel. keep_open, if relevant, and not specified, is False.

**kwargskeyword arguments

passed to opening method when fileish is str. Change of defaults as for *args

__init__(fileish: str | IOBase, *args, **kwargs)

bz2_def = (<class 'bz2.BZ2File'>, ('mode', 'buffering', 'compresslevel'))

close() → None

close_if_mine() → None

Close self.fobj iff we opened it in the constructor

property closed: bool

compress_ext_icase: bool = True

whether to ignore case looking for compression extensions

compress_ext_map: dict[str | None, OpenerDef] = {'.bz2': (<class 'bz2.BZ2File'>, ('mode', 'buffering', 'compresslevel')), '.gz': (<function gzip_open>, ('mode', 'compresslevel', 'mtime', 'keep_open')), '.zst': (<function zstd_open>, ('mode', 'level', 'option', 'zstd_dict')), None: (<built-in function open>, ('mode', 'buffering'))}

default_compresslevel = 1

default compression level when writing gz and bz2 files

default_zst_level = {'r': None, 'rb': None, 'w': 3, 'wb': 3}

default compression level for zst files

fileno() → int

fobj: io.IOBase

gz_def = (<function gzip_open>, ('mode', 'compresslevel', 'mtime', 'keep_open'))

property mode: str

property name: str | None

Return self.fobj.name or self._name if not present

self._name will be None if object was created with a fileobj, otherwise it will be the filename.

read(size: int = -1, /) → bytes

readinto(buffer: WriteableBuffer, /) → int | None

seek(pos: int, whence: int = 0, /) → int

tell() → int

write(b: bytes, /) → int | None

writelines(lines: ty.Iterable[ReadableBuffer], /) → None

zstd_def = (<function zstd_open>, ('mode', 'level', 'option', 'zstd_dict'))