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 throw 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# XXX edge cases when switching between reading/writing 38# XXX need to support 1 meaning line-buffered 39# XXX whenever an argument is None, use the default value 40# XXX read/write ops should check readable/writable 41# XXX buffered readinto should work with arbitrary buffer objects 42# XXX use incremental encoder for text output, at least for UTF-16 and UTF-8-SIG 43# XXX check writable, readable and seekable in appropriate places 44 45 46__author__ = ("Guido van Rossum <guido@python.org>, " 47 "Mike Verdone <mike.verdone@gmail.com>, " 48 "Mark Russell <mark.russell@zen.co.uk>, " 49 "Antoine Pitrou <solipsis@pitrou.net>, " 50 "Amaury Forgeot d'Arc <amauryfa@gmail.com>, " 51 "Benjamin Peterson <benjamin@python.org>") 52 53__all__ = ["BlockingIOError", "open", "IOBase", "RawIOBase", "FileIO", 54 "BytesIO", "StringIO", "BufferedIOBase", 55 "BufferedReader", "BufferedWriter", "BufferedRWPair", 56 "BufferedRandom", "TextIOBase", "TextIOWrapper", 57 "UnsupportedOperation", "SEEK_SET", "SEEK_CUR", "SEEK_END"] 58 59 60import _io 61import abc 62 63from _io import (DEFAULT_BUFFER_SIZE, BlockingIOError, UnsupportedOperation, 64 open, FileIO, BytesIO, StringIO, BufferedReader, 65 BufferedWriter, BufferedRWPair, BufferedRandom, 66 IncrementalNewlineDecoder, TextIOWrapper) 67 68OpenWrapper = _io.open # for compatibility with _pyio 69 70# for seek() 71SEEK_SET = 0 72SEEK_CUR = 1 73SEEK_END = 2 74 75# Declaring ABCs in C is tricky so we do it here. 76# Method descriptions and default implementations are inherited from the C 77# version however. 78class IOBase(_io._IOBase): 79 __metaclass__ = abc.ABCMeta 80 81class RawIOBase(_io._RawIOBase, IOBase): 82 pass 83 84class BufferedIOBase(_io._BufferedIOBase, IOBase): 85 pass 86 87class TextIOBase(_io._TextIOBase, IOBase): 88 pass 89 90RawIOBase.register(FileIO) 91 92for klass in (BytesIO, BufferedReader, BufferedWriter, BufferedRandom, 93 BufferedRWPair): 94 BufferedIOBase.register(klass) 95 96for klass in (StringIO, TextIOWrapper): 97 TextIOBase.register(klass) 98del klass 99