1 """The io module provides the Python interfaces to stream handling. The
2 builtin open function is defined in this module.
3 
4 At the top of the I/O hierarchy is the abstract base class IOBase. It
5 defines the basic interface to a stream. Note, however, that there is no
6 separation between reading and writing to streams; implementations are
7 allowed to raise an OSError if they do not support a given operation.
8 
9 Extending IOBase is RawIOBase which deals simply with the reading and
10 writing of raw bytes to a stream. FileIO subclasses RawIOBase to provide
11 an interface to OS files.
12 
13 BufferedIOBase deals with buffering on a raw byte stream (RawIOBase). Its
14 subclasses, BufferedWriter, BufferedReader, and BufferedRWPair buffer
15 streams that are readable, writable, and both respectively.
16 BufferedRandom provides a buffered interface to random access
17 streams. BytesIO is a simple stream of in-memory bytes.
18 
19 Another IOBase subclass, TextIOBase, deals with the encoding and decoding
20 of streams into text. TextIOWrapper, which extends it, is a buffered text
21 interface to a buffered raw stream (`BufferedIOBase`). Finally, StringIO
22 is an in-memory stream for text.
23 
24 Argument names are not part of the specification, and only the arguments
25 of open() are intended to be used as keyword arguments.
26 
27 data:
28 
29 DEFAULT_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 
51 import _io
52 import abc
53 
54 from _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 
60 def __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(f"module {__name__!r} has no attribute {name!r}")
74 
75 
76 # Pretend this exception was created here.
77 UnsupportedOperation.__module__ = "io"
78 
79 # for seek()
80 SEEK_SET = 0
81 SEEK_CUR = 1
82 SEEK_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.
87 class IOBase(_io._IOBase, metaclass=abc.ABCMeta):
88     __doc__ = _io._IOBase.__doc__
89 
90 class RawIOBase(_io._RawIOBase, IOBase):
91     __doc__ = _io._RawIOBase.__doc__
92 
93 class BufferedIOBase(_io._BufferedIOBase, IOBase):
94     __doc__ = _io._BufferedIOBase.__doc__
95 
96 class TextIOBase(_io._TextIOBase, IOBase):
97     __doc__ = _io._TextIOBase.__doc__
98 
99 RawIOBase.register(FileIO)
100 
101 for klass in (BytesIO, BufferedReader, BufferedWriter, BufferedRandom,
102               BufferedRWPair):
103     BufferedIOBase.register(klass)
104 
105 for klass in (StringIO, TextIOWrapper):
106     TextIOBase.register(klass)
107 del klass
108 
109 try:
110     from _io import _WindowsConsoleIO
111 except ImportError:
112     pass
113 else:
114     RawIOBase.register(_WindowsConsoleIO)
115