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1"""The io module provides the Python interfaces to stream handling. The
2builtin open function is defined in this module.
3
4At the top of the I/O hierarchy is the abstract base class IOBase. It
5defines the basic interface to a stream. Note, however, that there is no
6separation between reading and writing to streams; implementations are
7allowed to raise an OSError if they do not support a given operation.
8
9Extending IOBase is RawIOBase which deals simply with the reading and
10writing of raw bytes to a stream. FileIO subclasses RawIOBase to provide
11an interface to OS files.
12
13BufferedIOBase deals with buffering on a raw byte stream (RawIOBase). Its
14subclasses, BufferedWriter, BufferedReader, and BufferedRWPair buffer
15streams that are readable, writable, and both respectively.
16BufferedRandom provides a buffered interface to random access
17streams. BytesIO is a simple stream of in-memory bytes.
18
19Another IOBase subclass, TextIOBase, deals with the encoding and decoding
20of streams into text. TextIOWrapper, which extends it, is a buffered text
21interface to a buffered raw stream (`BufferedIOBase`). Finally, StringIO
22is an in-memory stream for text.
23
24Argument names are not part of the specification, and only the arguments
25of open() are intended to be used as keyword arguments.
26
27data:
28
29DEFAULT_BUFFER_SIZE
30
31   An int containing the default buffer size used by the module's buffered
32   I/O classes. open() uses the file's blksize (as obtained by os.stat) if
33   possible.
34"""
35# New I/O library conforming to PEP 3116.
36
37__author__ = ("Guido van Rossum <guido@python.org>, "
38              "Mike Verdone <mike.verdone@gmail.com>, "
39              "Mark Russell <mark.russell@zen.co.uk>, "
40              "Antoine Pitrou <solipsis@pitrou.net>, "
41              "Amaury Forgeot d'Arc <amauryfa@gmail.com>, "
42              "Benjamin Peterson <benjamin@python.org>")
43
44__all__ = ["BlockingIOError", "open", "open_code", "IOBase", "RawIOBase",
45           "FileIO", "BytesIO", "StringIO", "BufferedIOBase",
46           "BufferedReader", "BufferedWriter", "BufferedRWPair",
47           "BufferedRandom", "TextIOBase", "TextIOWrapper",
48           "UnsupportedOperation", "SEEK_SET", "SEEK_CUR", "SEEK_END"]
49
50
51import _io
52import abc
53
54from _io import (DEFAULT_BUFFER_SIZE, BlockingIOError, UnsupportedOperation,
55                 open, open_code, FileIO, BytesIO, StringIO, BufferedReader,
56                 BufferedWriter, BufferedRWPair, BufferedRandom,
57                 IncrementalNewlineDecoder, text_encoding, TextIOWrapper)
58
59
60def __getattr__(name):
61    if name == "OpenWrapper":
62        # bpo-43680: Until Python 3.9, _pyio.open was not a static method and
63        # builtins.open was set to OpenWrapper to not become a bound method
64        # when set to a class variable. _io.open is a built-in function whereas
65        # _pyio.open is a Python function. In Python 3.10, _pyio.open() is now
66        # a static method, and builtins.open() is now io.open().
67        import warnings
68        warnings.warn('OpenWrapper is deprecated, use open instead',
69                      DeprecationWarning, stacklevel=2)
70        global OpenWrapper
71        OpenWrapper = open
72        return OpenWrapper
73    raise AttributeError(name)
74
75
76# Pretend this exception was created here.
77UnsupportedOperation.__module__ = "io"
78
79# for seek()
80SEEK_SET = 0
81SEEK_CUR = 1
82SEEK_END = 2
83
84# Declaring ABCs in C is tricky so we do it here.
85# Method descriptions and default implementations are inherited from the C
86# version however.
87class IOBase(_io._IOBase, metaclass=abc.ABCMeta):
88    __doc__ = _io._IOBase.__doc__
89
90class RawIOBase(_io._RawIOBase, IOBase):
91    __doc__ = _io._RawIOBase.__doc__
92
93class BufferedIOBase(_io._BufferedIOBase, IOBase):
94    __doc__ = _io._BufferedIOBase.__doc__
95
96class TextIOBase(_io._TextIOBase, IOBase):
97    __doc__ = _io._TextIOBase.__doc__
98
99RawIOBase.register(FileIO)
100
101for klass in (BytesIO, BufferedReader, BufferedWriter, BufferedRandom,
102              BufferedRWPair):
103    BufferedIOBase.register(klass)
104
105for klass in (StringIO, TextIOWrapper):
106    TextIOBase.register(klass)
107del klass
108
109try:
110    from _io import _WindowsConsoleIO
111except ImportError:
112    pass
113else:
114    RawIOBase.register(_WindowsConsoleIO)
115