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 IOError 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 a 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", "IOBase", "RawIOBase", "FileIO",
45           "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, FileIO, BytesIO, StringIO, BufferedReader,
56                 BufferedWriter, BufferedRWPair, BufferedRandom,
57                 IncrementalNewlineDecoder, TextIOWrapper)
58
59OpenWrapper = _io.open # for compatibility with _pyio
60
61# for seek()
62SEEK_SET = 0
63SEEK_CUR = 1
64SEEK_END = 2
65
66# Declaring ABCs in C is tricky so we do it here.
67# Method descriptions and default implementations are inherited from the C
68# version however.
69class IOBase(_io._IOBase):
70    __metaclass__ = abc.ABCMeta
71
72class RawIOBase(_io._RawIOBase, IOBase):
73    pass
74
75class BufferedIOBase(_io._BufferedIOBase, IOBase):
76    pass
77
78class TextIOBase(_io._TextIOBase, IOBase):
79    pass
80
81RawIOBase.register(FileIO)
82
83for klass in (BytesIO, BufferedReader, BufferedWriter, BufferedRandom,
84              BufferedRWPair):
85    BufferedIOBase.register(klass)
86
87for klass in (StringIO, TextIOWrapper):
88    TextIOBase.register(klass)
89del klass
90