"""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",

"DEFAULT_BUFFER_SIZE", "text_encoding", "IncrementalNewlineDecoder",

"Reader", "Writer"]

import _io

import abc

from _collections_abc import _check_methods

from _io import (DEFAULT_BUFFER_SIZE, BlockingIOError, UnsupportedOperation,

open, open_code, FileIO, BytesIO, StringIO, BufferedReader,

BufferedWriter, BufferedRWPair, BufferedRandom,

IncrementalNewlineDecoder, text_encoding, TextIOWrapper)

# 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)

#

# Static Typing Support

#

GenericAlias = type(list[int])

class Reader(metaclass=abc.ABCMeta):

"""Protocol for simple I/O reader instances.

This protocol only supports blocking I/O.

"""

__slots__ = ()

@abc.abstractmethod

def read(self, size=..., /):

"""Read data from the input stream and return it.

If *size* is specified, at most *size* items (bytes/characters) will be

read.

"""

@classmethod

def __subclasshook__(cls, C):

if cls is Reader:

return _check_methods(C, "read")

return NotImplemented

__class_getitem__ = classmethod(GenericAlias)

class Writer(metaclass=abc.ABCMeta):

"""Protocol for simple I/O writer instances.

This protocol only supports blocking I/O.

"""

__slots__ = ()

@abc.abstractmethod

def write(self, data, /):

"""Write *data* to the output stream and return the number of items written."""

@classmethod

def __subclasshook__(cls, C):

if cls is Writer:

return _check_methods(C, "write")

return NotImplemented

__class_getitem__ = classmethod(GenericAlias)