cpython/Lib/io.py
Victor Stinner 3bc694d5f3
bpo-43680: Deprecate io.OpenWrapper (GH-25357)
Deprecate io.OpenWrapper and _pyio.OpenWrapper: use io.open and
_pyio.open instead. Until Python 3.9, _pyio.open was not a static
method and builtins.open was set to OpenWrapper to not become a bound
method when set to a class variable. _io.open is a built-in function
whereas _pyio.open is a Python function. In Python 3.10, _pyio.open()
is now a static method, and builtins.open() is now io.open().
2021-04-14 03:24:33 +02:00

114 lines
4.1 KiB
Python

"""The io module provides the Python interfaces to stream handling. The
builtin open function is defined in this module.
At the top of the I/O hierarchy is the abstract base class IOBase. It
defines the basic interface to a stream. Note, however, that there is no
separation between reading and writing to streams; implementations are
allowed to raise an OSError if they do not support a given operation.
Extending IOBase is RawIOBase which deals simply with the reading and
writing of raw bytes to a stream. FileIO subclasses RawIOBase to provide
an interface to OS files.
BufferedIOBase deals with buffering on a raw byte stream (RawIOBase). Its
subclasses, BufferedWriter, BufferedReader, and BufferedRWPair buffer
streams that are readable, writable, and both respectively.
BufferedRandom provides a buffered interface to random access
streams. BytesIO is a simple stream of in-memory bytes.
Another IOBase subclass, TextIOBase, deals with the encoding and decoding
of streams into text. TextIOWrapper, which extends it, is a buffered text
interface to a buffered raw stream (`BufferedIOBase`). Finally, StringIO
is an in-memory stream for text.
Argument names are not part of the specification, and only the arguments
of open() are intended to be used as keyword arguments.
data:
DEFAULT_BUFFER_SIZE
An int containing the default buffer size used by the module's buffered
I/O classes. open() uses the file's blksize (as obtained by os.stat) if
possible.
"""
# New I/O library conforming to PEP 3116.
__author__ = ("Guido van Rossum <guido@python.org>, "
"Mike Verdone <mike.verdone@gmail.com>, "
"Mark Russell <mark.russell@zen.co.uk>, "
"Antoine Pitrou <solipsis@pitrou.net>, "
"Amaury Forgeot d'Arc <amauryfa@gmail.com>, "
"Benjamin Peterson <benjamin@python.org>")
__all__ = ["BlockingIOError", "open", "open_code", "IOBase", "RawIOBase",
"FileIO", "BytesIO", "StringIO", "BufferedIOBase",
"BufferedReader", "BufferedWriter", "BufferedRWPair",
"BufferedRandom", "TextIOBase", "TextIOWrapper",
"UnsupportedOperation", "SEEK_SET", "SEEK_CUR", "SEEK_END"]
import _io
import abc
from _io import (DEFAULT_BUFFER_SIZE, BlockingIOError, UnsupportedOperation,
open, open_code, FileIO, BytesIO, StringIO, BufferedReader,
BufferedWriter, BufferedRWPair, BufferedRandom,
IncrementalNewlineDecoder, text_encoding, TextIOWrapper)
def __getattr__(name):
if name == "OpenWrapper":
# bpo-43680: Until Python 3.9, _pyio.open was not a static method and
# builtins.open was set to OpenWrapper to not become a bound method
# when set to a class variable. _io.open is a built-in function whereas
# _pyio.open is a Python function. In Python 3.10, _pyio.open() is now
# a static method, and builtins.open() is now io.open().
import warnings
warnings.warn('OpenWrapper is deprecated, use open instead',
DeprecationWarning, stacklevel=2)
global OpenWrapper
OpenWrapper = open
return OpenWrapper
raise AttributeError(name)
# Pretend this exception was created here.
UnsupportedOperation.__module__ = "io"
# for seek()
SEEK_SET = 0
SEEK_CUR = 1
SEEK_END = 2
# Declaring ABCs in C is tricky so we do it here.
# Method descriptions and default implementations are inherited from the C
# version however.
class IOBase(_io._IOBase, metaclass=abc.ABCMeta):
__doc__ = _io._IOBase.__doc__
class RawIOBase(_io._RawIOBase, IOBase):
__doc__ = _io._RawIOBase.__doc__
class BufferedIOBase(_io._BufferedIOBase, IOBase):
__doc__ = _io._BufferedIOBase.__doc__
class TextIOBase(_io._TextIOBase, IOBase):
__doc__ = _io._TextIOBase.__doc__
RawIOBase.register(FileIO)
for klass in (BytesIO, BufferedReader, BufferedWriter, BufferedRandom,
BufferedRWPair):
BufferedIOBase.register(klass)
for klass in (StringIO, TextIOWrapper):
TextIOBase.register(klass)
del klass
try:
from _io import _WindowsConsoleIO
except ImportError:
pass
else:
RawIOBase.register(_WindowsConsoleIO)