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| """ codecs -- Python Codec Registry, API and helpers. | |
| Written by Marc-Andre Lemburg (mal@lemburg.com). | |
| (c) Copyright CNRI, All Rights Reserved. NO WARRANTY. | |
| """ | |
| import builtins | |
| import sys | |
| ### Registry and builtin stateless codec functions | |
| try: | |
| from _codecs import * | |
| except ImportError as why: | |
| raise SystemError('Failed to load the builtin codecs: %s' % why) | |
| __all__ = ["register", "lookup", "open", "EncodedFile", "BOM", "BOM_BE", | |
| "BOM_LE", "BOM32_BE", "BOM32_LE", "BOM64_BE", "BOM64_LE", | |
| "BOM_UTF8", "BOM_UTF16", "BOM_UTF16_LE", "BOM_UTF16_BE", | |
| "BOM_UTF32", "BOM_UTF32_LE", "BOM_UTF32_BE", | |
| "CodecInfo", "Codec", "IncrementalEncoder", "IncrementalDecoder", | |
| "StreamReader", "StreamWriter", | |
| "StreamReaderWriter", "StreamRecoder", | |
| "getencoder", "getdecoder", "getincrementalencoder", | |
| "getincrementaldecoder", "getreader", "getwriter", | |
| "encode", "decode", "iterencode", "iterdecode", | |
| "strict_errors", "ignore_errors", "replace_errors", | |
| "xmlcharrefreplace_errors", | |
| "backslashreplace_errors", "namereplace_errors", | |
| "register_error", "lookup_error"] | |
| ### Constants | |
| # | |
| # Byte Order Mark (BOM = ZERO WIDTH NO-BREAK SPACE = U+FEFF) | |
| # and its possible byte string values | |
| # for UTF8/UTF16/UTF32 output and little/big endian machines | |
| # | |
| # UTF-8 | |
| BOM_UTF8 = b'\xef\xbb\xbf' | |
| # UTF-16, little endian | |
| BOM_LE = BOM_UTF16_LE = b'\xff\xfe' | |
| # UTF-16, big endian | |
| BOM_BE = BOM_UTF16_BE = b'\xfe\xff' | |
| # UTF-32, little endian | |
| BOM_UTF32_LE = b'\xff\xfe\x00\x00' | |
| # UTF-32, big endian | |
| BOM_UTF32_BE = b'\x00\x00\xfe\xff' | |
| if sys.byteorder == 'little': | |
| # UTF-16, native endianness | |
| BOM = BOM_UTF16 = BOM_UTF16_LE | |
| # UTF-32, native endianness | |
| BOM_UTF32 = BOM_UTF32_LE | |
| else: | |
| # UTF-16, native endianness | |
| BOM = BOM_UTF16 = BOM_UTF16_BE | |
| # UTF-32, native endianness | |
| BOM_UTF32 = BOM_UTF32_BE | |
| # Old broken names (don't use in new code) | |
| BOM32_LE = BOM_UTF16_LE | |
| BOM32_BE = BOM_UTF16_BE | |
| BOM64_LE = BOM_UTF32_LE | |
| BOM64_BE = BOM_UTF32_BE | |
| ### Codec base classes (defining the API) | |
| class CodecInfo(tuple): | |
| """Codec details when looking up the codec registry""" | |
| # Private API to allow Python 3.4 to blacklist the known non-Unicode | |
| # codecs in the standard library. A more general mechanism to | |
| # reliably distinguish test encodings from other codecs will hopefully | |
| # be defined for Python 3.5 | |
| # | |
| # See http://bugs.python.org/issue19619 | |
| _is_text_encoding = True # Assume codecs are text encodings by default | |
| def __new__(cls, encode, decode, streamreader=None, streamwriter=None, | |
| incrementalencoder=None, incrementaldecoder=None, name=None, | |
| *, _is_text_encoding=None): | |
| self = tuple.__new__(cls, (encode, decode, streamreader, streamwriter)) | |
| self.name = name | |
| self.encode = encode | |
| self.decode = decode | |
| self.incrementalencoder = incrementalencoder | |
| self.incrementaldecoder = incrementaldecoder | |
| self.streamwriter = streamwriter | |
| self.streamreader = streamreader | |
| if _is_text_encoding is not None: | |
| self._is_text_encoding = _is_text_encoding | |
| return self | |
| def __repr__(self): | |
| return "<%s.%s object for encoding %s at %#x>" % \ | |
| (self.__class__.__module__, self.__class__.__qualname__, | |
| self.name, id(self)) | |
| class Codec: | |
| """ Defines the interface for stateless encoders/decoders. | |
| The .encode()/.decode() methods may use different error | |
| handling schemes by providing the errors argument. These | |
| string values are predefined: | |
| 'strict' - raise a ValueError error (or a subclass) | |
| 'ignore' - ignore the character and continue with the next | |
| 'replace' - replace with a suitable replacement character; | |
| Python will use the official U+FFFD REPLACEMENT | |
| CHARACTER for the builtin Unicode codecs on | |
| decoding and '?' on encoding. | |
| 'surrogateescape' - replace with private code points U+DCnn. | |
| 'xmlcharrefreplace' - Replace with the appropriate XML | |
| character reference (only for encoding). | |
| 'backslashreplace' - Replace with backslashed escape sequences. | |
| 'namereplace' - Replace with \\N{...} escape sequences | |
| (only for encoding). | |
| The set of allowed values can be extended via register_error. | |
| """ | |
| def encode(self, input, errors='strict'): | |
| """ Encodes the object input and returns a tuple (output | |
| object, length consumed). | |
| errors defines the error handling to apply. It defaults to | |
| 'strict' handling. | |
| The method may not store state in the Codec instance. Use | |
| StreamWriter for codecs which have to keep state in order to | |
| make encoding efficient. | |
| The encoder must be able to handle zero length input and | |
| return an empty object of the output object type in this | |
| situation. | |
| """ | |
| raise NotImplementedError | |
| def decode(self, input, errors='strict'): | |
| """ Decodes the object input and returns a tuple (output | |
| object, length consumed). | |
| input must be an object which provides the bf_getreadbuf | |
| buffer slot. Python strings, buffer objects and memory | |
| mapped files are examples of objects providing this slot. | |
| errors defines the error handling to apply. It defaults to | |
| 'strict' handling. | |
| The method may not store state in the Codec instance. Use | |
| StreamReader for codecs which have to keep state in order to | |
| make decoding efficient. | |
| The decoder must be able to handle zero length input and | |
| return an empty object of the output object type in this | |
| situation. | |
| """ | |
| raise NotImplementedError | |
| class IncrementalEncoder(object): | |
| """ | |
| An IncrementalEncoder encodes an input in multiple steps. The input can | |
| be passed piece by piece to the encode() method. The IncrementalEncoder | |
| remembers the state of the encoding process between calls to encode(). | |
| """ | |
| def __init__(self, errors='strict'): | |
| """ | |
| Creates an IncrementalEncoder instance. | |
| The IncrementalEncoder may use different error handling schemes by | |
| providing the errors keyword argument. See the module docstring | |
| for a list of possible values. | |
| """ | |
| self.errors = errors | |
| self.buffer = "" | |
| def encode(self, input, final=False): | |
| """ | |
| Encodes input and returns the resulting object. | |
| """ | |
| raise NotImplementedError | |
| def reset(self): | |
| """ | |
| Resets the encoder to the initial state. | |
| """ | |
| def getstate(self): | |
| """ | |
| Return the current state of the encoder. | |
| """ | |
| return 0 | |
| def setstate(self, state): | |
| """ | |
| Set the current state of the encoder. state must have been | |
| returned by getstate(). | |
| """ | |
| class BufferedIncrementalEncoder(IncrementalEncoder): | |
| """ | |
| This subclass of IncrementalEncoder can be used as the baseclass for an | |
| incremental encoder if the encoder must keep some of the output in a | |
| buffer between calls to encode(). | |
| """ | |
| def __init__(self, errors='strict'): | |
| IncrementalEncoder.__init__(self, errors) | |
| # unencoded input that is kept between calls to encode() | |
| self.buffer = "" | |
| def _buffer_encode(self, input, errors, final): | |
| # Overwrite this method in subclasses: It must encode input | |
| # and return an (output, length consumed) tuple | |
| raise NotImplementedError | |
| def encode(self, input, final=False): | |
| # encode input (taking the buffer into account) | |
| data = self.buffer + input | |
| (result, consumed) = self._buffer_encode(data, self.errors, final) | |
| # keep unencoded input until the next call | |
| self.buffer = data[consumed:] | |
| return result | |
| def reset(self): | |
| IncrementalEncoder.reset(self) | |
| self.buffer = "" | |
| def getstate(self): | |
| return self.buffer or 0 | |
| def setstate(self, state): | |
| self.buffer = state or "" | |
| class IncrementalDecoder(object): | |
| """ | |
| An IncrementalDecoder decodes an input in multiple steps. The input can | |
| be passed piece by piece to the decode() method. The IncrementalDecoder | |
| remembers the state of the decoding process between calls to decode(). | |
| """ | |
| def __init__(self, errors='strict'): | |
| """ | |
| Create an IncrementalDecoder instance. | |
| The IncrementalDecoder may use different error handling schemes by | |
| providing the errors keyword argument. See the module docstring | |
| for a list of possible values. | |
| """ | |
| self.errors = errors | |
| def decode(self, input, final=False): | |
| """ | |
| Decode input and returns the resulting object. | |
| """ | |
| raise NotImplementedError | |
| def reset(self): | |
| """ | |
| Reset the decoder to the initial state. | |
| """ | |
| def getstate(self): | |
| """ | |
| Return the current state of the decoder. | |
| This must be a (buffered_input, additional_state_info) tuple. | |
| buffered_input must be a bytes object containing bytes that | |
| were passed to decode() that have not yet been converted. | |
| additional_state_info must be a non-negative integer | |
| representing the state of the decoder WITHOUT yet having | |
| processed the contents of buffered_input. In the initial state | |
| and after reset(), getstate() must return (b"", 0). | |
| """ | |
| return (b"", 0) | |
| def setstate(self, state): | |
| """ | |
| Set the current state of the decoder. | |
| state must have been returned by getstate(). The effect of | |
| setstate((b"", 0)) must be equivalent to reset(). | |
| """ | |
| class BufferedIncrementalDecoder(IncrementalDecoder): | |
| """ | |
| This subclass of IncrementalDecoder can be used as the baseclass for an | |
| incremental decoder if the decoder must be able to handle incomplete | |
| byte sequences. | |
| """ | |
| def __init__(self, errors='strict'): | |
| IncrementalDecoder.__init__(self, errors) | |
| # undecoded input that is kept between calls to decode() | |
| self.buffer = b"" | |
| def _buffer_decode(self, input, errors, final): | |
| # Overwrite this method in subclasses: It must decode input | |
| # and return an (output, length consumed) tuple | |
| raise NotImplementedError | |
| def decode(self, input, final=False): | |
| # decode input (taking the buffer into account) | |
| data = self.buffer + input | |
| (result, consumed) = self._buffer_decode(data, self.errors, final) | |
| # keep undecoded input until the next call | |
| self.buffer = data[consumed:] | |
| return result | |
| def reset(self): | |
| IncrementalDecoder.reset(self) | |
| self.buffer = b"" | |
| def getstate(self): | |
| # additional state info is always 0 | |
| return (self.buffer, 0) | |
| def setstate(self, state): | |
| # ignore additional state info | |
| self.buffer = state[0] | |
| # | |
| # The StreamWriter and StreamReader class provide generic working | |
| # interfaces which can be used to implement new encoding submodules | |
| # very easily. See encodings/utf_8.py for an example on how this is | |
| # done. | |
| # | |
| class StreamWriter(Codec): | |
| def __init__(self, stream, errors='strict'): | |
| """ Creates a StreamWriter instance. | |
| stream must be a file-like object open for writing. | |
| The StreamWriter may use different error handling | |
| schemes by providing the errors keyword argument. These | |
| parameters are predefined: | |
| 'strict' - raise a ValueError (or a subclass) | |
| 'ignore' - ignore the character and continue with the next | |
| 'replace'- replace with a suitable replacement character | |
| 'xmlcharrefreplace' - Replace with the appropriate XML | |
| character reference. | |
| 'backslashreplace' - Replace with backslashed escape | |
| sequences. | |
| 'namereplace' - Replace with \\N{...} escape sequences. | |
| The set of allowed parameter values can be extended via | |
| register_error. | |
| """ | |
| self.stream = stream | |
| self.errors = errors | |
| def write(self, object): | |
| """ Writes the object's contents encoded to self.stream. | |
| """ | |
| data, consumed = self.encode(object, self.errors) | |
| self.stream.write(data) | |
| def writelines(self, list): | |
| """ Writes the concatenated list of strings to the stream | |
| using .write(). | |
| """ | |
| self.write(''.join(list)) | |
| def reset(self): | |
| """ Flushes and resets the codec buffers used for keeping state. | |
| Calling this method should ensure that the data on the | |
| output is put into a clean state, that allows appending | |
| of new fresh data without having to rescan the whole | |
| stream to recover state. | |
| """ | |
| pass | |
| def seek(self, offset, whence=0): | |
| self.stream.seek(offset, whence) | |
| if whence == 0 and offset == 0: | |
| self.reset() | |
| def __getattr__(self, name, | |
| getattr=getattr): | |
| """ Inherit all other methods from the underlying stream. | |
| """ | |
| return getattr(self.stream, name) | |
| def __enter__(self): | |
| return self | |
| def __exit__(self, type, value, tb): | |
| self.stream.close() | |
| ### | |
| class StreamReader(Codec): | |
| charbuffertype = str | |
| def __init__(self, stream, errors='strict'): | |
| """ Creates a StreamReader instance. | |
| stream must be a file-like object open for reading. | |
| The StreamReader may use different error handling | |
| schemes by providing the errors keyword argument. These | |
| parameters are predefined: | |
| 'strict' - raise a ValueError (or a subclass) | |
| 'ignore' - ignore the character and continue with the next | |
| 'replace'- replace with a suitable replacement character | |
| 'backslashreplace' - Replace with backslashed escape sequences; | |
| The set of allowed parameter values can be extended via | |
| register_error. | |
| """ | |
| self.stream = stream | |
| self.errors = errors | |
| self.bytebuffer = b"" | |
| self._empty_charbuffer = self.charbuffertype() | |
| self.charbuffer = self._empty_charbuffer | |
| self.linebuffer = None | |
| def decode(self, input, errors='strict'): | |
| raise NotImplementedError | |
| def read(self, size=-1, chars=-1, firstline=False): | |
| """ Decodes data from the stream self.stream and returns the | |
| resulting object. | |
| chars indicates the number of decoded code points or bytes to | |
| return. read() will never return more data than requested, | |
| but it might return less, if there is not enough available. | |
| size indicates the approximate maximum number of decoded | |
| bytes or code points to read for decoding. The decoder | |
| can modify this setting as appropriate. The default value | |
| -1 indicates to read and decode as much as possible. size | |
| is intended to prevent having to decode huge files in one | |
| step. | |
| If firstline is true, and a UnicodeDecodeError happens | |
| after the first line terminator in the input only the first line | |
| will be returned, the rest of the input will be kept until the | |
| next call to read(). | |
| The method should use a greedy read strategy, meaning that | |
| it should read as much data as is allowed within the | |
| definition of the encoding and the given size, e.g. if | |
| optional encoding endings or state markers are available | |
| on the stream, these should be read too. | |
| """ | |
| # If we have lines cached, first merge them back into characters | |
| if self.linebuffer: | |
| self.charbuffer = self._empty_charbuffer.join(self.linebuffer) | |
| self.linebuffer = None | |
| if chars < 0: | |
| # For compatibility with other read() methods that take a | |
| # single argument | |
| chars = size | |
| # read until we get the required number of characters (if available) | |
| while True: | |
| # can the request be satisfied from the character buffer? | |
| if chars >= 0: | |
| if len(self.charbuffer) >= chars: | |
| break | |
| # we need more data | |
| if size < 0: | |
| newdata = self.stream.read() | |
| else: | |
| newdata = self.stream.read(size) | |
| # decode bytes (those remaining from the last call included) | |
| data = self.bytebuffer + newdata | |
| if not data: | |
| break | |
| try: | |
| newchars, decodedbytes = self.decode(data, self.errors) | |
| except UnicodeDecodeError as exc: | |
| if firstline: | |
| newchars, decodedbytes = \ | |
| self.decode(data[:exc.start], self.errors) | |
| lines = newchars.splitlines(keepends=True) | |
| if len(lines)<=1: | |
| raise | |
| else: | |
| raise | |
| # keep undecoded bytes until the next call | |
| self.bytebuffer = data[decodedbytes:] | |
| # put new characters in the character buffer | |
| self.charbuffer += newchars | |
| # there was no data available | |
| if not newdata: | |
| break | |
| if chars < 0: | |
| # Return everything we've got | |
| result = self.charbuffer | |
| self.charbuffer = self._empty_charbuffer | |
| else: | |
| # Return the first chars characters | |
| result = self.charbuffer[:chars] | |
| self.charbuffer = self.charbuffer[chars:] | |
| return result | |
| def readline(self, size=None, keepends=True): | |
| """ Read one line from the input stream and return the | |
| decoded data. | |
| size, if given, is passed as size argument to the | |
| read() method. | |
| """ | |
| # If we have lines cached from an earlier read, return | |
| # them unconditionally | |
| if self.linebuffer: | |
| line = self.linebuffer[0] | |
| del self.linebuffer[0] | |
| if len(self.linebuffer) == 1: | |
| # revert to charbuffer mode; we might need more data | |
| # next time | |
| self.charbuffer = self.linebuffer[0] | |
| self.linebuffer = None | |
| if not keepends: | |
| line = line.splitlines(keepends=False)[0] | |
| return line | |
| readsize = size or 72 | |
| line = self._empty_charbuffer | |
| # If size is given, we call read() only once | |
| while True: | |
| data = self.read(readsize, firstline=True) | |
| if data: | |
| # If we're at a "\r" read one extra character (which might | |
| # be a "\n") to get a proper line ending. If the stream is | |
| # temporarily exhausted we return the wrong line ending. | |
| if (isinstance(data, str) and data.endswith("\r")) or \ | |
| (isinstance(data, bytes) and data.endswith(b"\r")): | |
| data += self.read(size=1, chars=1) | |
| line += data | |
| lines = line.splitlines(keepends=True) | |
| if lines: | |
| if len(lines) > 1: | |
| # More than one line result; the first line is a full line | |
| # to return | |
| line = lines[0] | |
| del lines[0] | |
| if len(lines) > 1: | |
| # cache the remaining lines | |
| lines[-1] += self.charbuffer | |
| self.linebuffer = lines | |
| self.charbuffer = None | |
| else: | |
| # only one remaining line, put it back into charbuffer | |
| self.charbuffer = lines[0] + self.charbuffer | |
| if not keepends: | |
| line = line.splitlines(keepends=False)[0] | |
| break | |
| line0withend = lines[0] | |
| line0withoutend = lines[0].splitlines(keepends=False)[0] | |
| if line0withend != line0withoutend: # We really have a line end | |
| # Put the rest back together and keep it until the next call | |
| self.charbuffer = self._empty_charbuffer.join(lines[1:]) + \ | |
| self.charbuffer | |
| if keepends: | |
| line = line0withend | |
| else: | |
| line = line0withoutend | |
| break | |
| # we didn't get anything or this was our only try | |
| if not data or size is not None: | |
| if line and not keepends: | |
| line = line.splitlines(keepends=False)[0] | |
| break | |
| if readsize < 8000: | |
| readsize *= 2 | |
| return line | |
| def readlines(self, sizehint=None, keepends=True): | |
| """ Read all lines available on the input stream | |
| and return them as a list. | |
| Line breaks are implemented using the codec's decoder | |
| method and are included in the list entries. | |
| sizehint, if given, is ignored since there is no efficient | |
| way to finding the true end-of-line. | |
| """ | |
| data = self.read() | |
| return data.splitlines(keepends) | |
| def reset(self): | |
| """ Resets the codec buffers used for keeping state. | |
| Note that no stream repositioning should take place. | |
| This method is primarily intended to be able to recover | |
| from decoding errors. | |
| """ | |
| self.bytebuffer = b"" | |
| self.charbuffer = self._empty_charbuffer | |
| self.linebuffer = None | |
| def seek(self, offset, whence=0): | |
| """ Set the input stream's current position. | |
| Resets the codec buffers used for keeping state. | |
| """ | |
| self.stream.seek(offset, whence) | |
| self.reset() | |
| def __next__(self): | |
| """ Return the next decoded line from the input stream.""" | |
| line = self.readline() | |
| if line: | |
| return line | |
| raise StopIteration | |
| def __iter__(self): | |
| return self | |
| def __getattr__(self, name, | |
| getattr=getattr): | |
| """ Inherit all other methods from the underlying stream. | |
| """ | |
| return getattr(self.stream, name) | |
| def __enter__(self): | |
| return self | |
| def __exit__(self, type, value, tb): | |
| self.stream.close() | |
| ### | |
| class StreamReaderWriter: | |
| """ StreamReaderWriter instances allow wrapping streams which | |
| work in both read and write modes. | |
| The design is such that one can use the factory functions | |
| returned by the codec.lookup() function to construct the | |
| instance. | |
| """ | |
| # Optional attributes set by the file wrappers below | |
| encoding = 'unknown' | |
| def __init__(self, stream, Reader, Writer, errors='strict'): | |
| """ Creates a StreamReaderWriter instance. | |
| stream must be a Stream-like object. | |
| Reader, Writer must be factory functions or classes | |
| providing the StreamReader, StreamWriter interface resp. | |
| Error handling is done in the same way as defined for the | |
| StreamWriter/Readers. | |
| """ | |
| self.stream = stream | |
| self.reader = Reader(stream, errors) | |
| self.writer = Writer(stream, errors) | |
| self.errors = errors | |
| def read(self, size=-1): | |
| return self.reader.read(size) | |
| def readline(self, size=None): | |
| return self.reader.readline(size) | |
| def readlines(self, sizehint=None): | |
| return self.reader.readlines(sizehint) | |
| def __next__(self): | |
| """ Return the next decoded line from the input stream.""" | |
| return next(self.reader) | |
| def __iter__(self): | |
| return self | |
| def write(self, data): | |
| return self.writer.write(data) | |
| def writelines(self, list): | |
| return self.writer.writelines(list) | |
| def reset(self): | |
| self.reader.reset() | |
| self.writer.reset() | |
| def seek(self, offset, whence=0): | |
| self.stream.seek(offset, whence) | |
| self.reader.reset() | |
| if whence == 0 and offset == 0: | |
| self.writer.reset() | |
| def __getattr__(self, name, | |
| getattr=getattr): | |
| """ Inherit all other methods from the underlying stream. | |
| """ | |
| return getattr(self.stream, name) | |
| # these are needed to make "with StreamReaderWriter(...)" work properly | |
| def __enter__(self): | |
| return self | |
| def __exit__(self, type, value, tb): | |
| self.stream.close() | |
| ### | |
| class StreamRecoder: | |
| """ StreamRecoder instances translate data from one encoding to another. | |
| They use the complete set of APIs returned by the | |
| codecs.lookup() function to implement their task. | |
| Data written to the StreamRecoder is first decoded into an | |
| intermediate format (depending on the "decode" codec) and then | |
| written to the underlying stream using an instance of the provided | |
| Writer class. | |
| In the other direction, data is read from the underlying stream using | |
| a Reader instance and then encoded and returned to the caller. | |
| """ | |
| # Optional attributes set by the file wrappers below | |
| data_encoding = 'unknown' | |
| file_encoding = 'unknown' | |
| def __init__(self, stream, encode, decode, Reader, Writer, | |
| errors='strict'): | |
| """ Creates a StreamRecoder instance which implements a two-way | |
| conversion: encode and decode work on the frontend (the | |
| data visible to .read() and .write()) while Reader and Writer | |
| work on the backend (the data in stream). | |
| You can use these objects to do transparent | |
| transcodings from e.g. latin-1 to utf-8 and back. | |
| stream must be a file-like object. | |
| encode and decode must adhere to the Codec interface; Reader and | |
| Writer must be factory functions or classes providing the | |
| StreamReader and StreamWriter interfaces resp. | |
| Error handling is done in the same way as defined for the | |
| StreamWriter/Readers. | |
| """ | |
| self.stream = stream | |
| self.encode = encode | |
| self.decode = decode | |
| self.reader = Reader(stream, errors) | |
| self.writer = Writer(stream, errors) | |
| self.errors = errors | |
| def read(self, size=-1): | |
| data = self.reader.read(size) | |
| data, bytesencoded = self.encode(data, self.errors) | |
| return data | |
| def readline(self, size=None): | |
| if size is None: | |
| data = self.reader.readline() | |
| else: | |
| data = self.reader.readline(size) | |
| data, bytesencoded = self.encode(data, self.errors) | |
| return data | |
| def readlines(self, sizehint=None): | |
| data = self.reader.read() | |
| data, bytesencoded = self.encode(data, self.errors) | |
| return data.splitlines(keepends=True) | |
| def __next__(self): | |
| """ Return the next decoded line from the input stream.""" | |
| data = next(self.reader) | |
| data, bytesencoded = self.encode(data, self.errors) | |
| return data | |
| def __iter__(self): | |
| return self | |
| def write(self, data): | |
| data, bytesdecoded = self.decode(data, self.errors) | |
| return self.writer.write(data) | |
| def writelines(self, list): | |
| data = b''.join(list) | |
| data, bytesdecoded = self.decode(data, self.errors) | |
| return self.writer.write(data) | |
| def reset(self): | |
| self.reader.reset() | |
| self.writer.reset() | |
| def seek(self, offset, whence=0): | |
| # Seeks must be propagated to both the readers and writers | |
| # as they might need to reset their internal buffers. | |
| self.reader.seek(offset, whence) | |
| self.writer.seek(offset, whence) | |
| def __getattr__(self, name, | |
| getattr=getattr): | |
| """ Inherit all other methods from the underlying stream. | |
| """ | |
| return getattr(self.stream, name) | |
| def __enter__(self): | |
| return self | |
| def __exit__(self, type, value, tb): | |
| self.stream.close() | |
| ### Shortcuts | |
| def open(filename, mode='r', encoding=None, errors='strict', buffering=-1): | |
| """ Open an encoded file using the given mode and return | |
| a wrapped version providing transparent encoding/decoding. | |
| Note: The wrapped version will only accept the object format | |
| defined by the codecs, i.e. Unicode objects for most builtin | |
| codecs. Output is also codec dependent and will usually be | |
| Unicode as well. | |
| Underlying encoded files are always opened in binary mode. | |
| The default file mode is 'r', meaning to open the file in read mode. | |
| encoding specifies the encoding which is to be used for the | |
| file. | |
| errors may be given to define the error handling. It defaults | |
| to 'strict' which causes ValueErrors to be raised in case an | |
| encoding error occurs. | |
| buffering has the same meaning as for the builtin open() API. | |
| It defaults to -1 which means that the default buffer size will | |
| be used. | |
| The returned wrapped file object provides an extra attribute | |
| .encoding which allows querying the used encoding. This | |
| attribute is only available if an encoding was specified as | |
| parameter. | |
| """ | |
| if encoding is not None and \ | |
| 'b' not in mode: | |
| # Force opening of the file in binary mode | |
| mode = mode + 'b' | |
| file = builtins.open(filename, mode, buffering) | |
| if encoding is None: | |
| return file | |
| try: | |
| info = lookup(encoding) | |
| srw = StreamReaderWriter(file, info.streamreader, info.streamwriter, errors) | |
| # Add attributes to simplify introspection | |
| srw.encoding = encoding | |
| return srw | |
| except: | |
| file.close() | |
| raise | |
| def EncodedFile(file, data_encoding, file_encoding=None, errors='strict'): | |
| """ Return a wrapped version of file which provides transparent | |
| encoding translation. | |
| Data written to the wrapped file is decoded according | |
| to the given data_encoding and then encoded to the underlying | |
| file using file_encoding. The intermediate data type | |
| will usually be Unicode but depends on the specified codecs. | |
| Bytes read from the file are decoded using file_encoding and then | |
| passed back to the caller encoded using data_encoding. | |
| If file_encoding is not given, it defaults to data_encoding. | |
| errors may be given to define the error handling. It defaults | |
| to 'strict' which causes ValueErrors to be raised in case an | |
| encoding error occurs. | |
| The returned wrapped file object provides two extra attributes | |
| .data_encoding and .file_encoding which reflect the given | |
| parameters of the same name. The attributes can be used for | |
| introspection by Python programs. | |
| """ | |
| if file_encoding is None: | |
| file_encoding = data_encoding | |
| data_info = lookup(data_encoding) | |
| file_info = lookup(file_encoding) | |
| sr = StreamRecoder(file, data_info.encode, data_info.decode, | |
| file_info.streamreader, file_info.streamwriter, errors) | |
| # Add attributes to simplify introspection | |
| sr.data_encoding = data_encoding | |
| sr.file_encoding = file_encoding | |
| return sr | |
| ### Helpers for codec lookup | |
| def getencoder(encoding): | |
| """ Lookup up the codec for the given encoding and return | |
| its encoder function. | |
| Raises a LookupError in case the encoding cannot be found. | |
| """ | |
| return lookup(encoding).encode | |
| def getdecoder(encoding): | |
| """ Lookup up the codec for the given encoding and return | |
| its decoder function. | |
| Raises a LookupError in case the encoding cannot be found. | |
| """ | |
| return lookup(encoding).decode | |
| def getincrementalencoder(encoding): | |
| """ Lookup up the codec for the given encoding and return | |
| its IncrementalEncoder class or factory function. | |
| Raises a LookupError in case the encoding cannot be found | |
| or the codecs doesn't provide an incremental encoder. | |
| """ | |
| encoder = lookup(encoding).incrementalencoder | |
| if encoder is None: | |
| raise LookupError(encoding) | |
| return encoder | |
| def getincrementaldecoder(encoding): | |
| """ Lookup up the codec for the given encoding and return | |
| its IncrementalDecoder class or factory function. | |
| Raises a LookupError in case the encoding cannot be found | |
| or the codecs doesn't provide an incremental decoder. | |
| """ | |
| decoder = lookup(encoding).incrementaldecoder | |
| if decoder is None: | |
| raise LookupError(encoding) | |
| return decoder | |
| def getreader(encoding): | |
| """ Lookup up the codec for the given encoding and return | |
| its StreamReader class or factory function. | |
| Raises a LookupError in case the encoding cannot be found. | |
| """ | |
| return lookup(encoding).streamreader | |
| def getwriter(encoding): | |
| """ Lookup up the codec for the given encoding and return | |
| its StreamWriter class or factory function. | |
| Raises a LookupError in case the encoding cannot be found. | |
| """ | |
| return lookup(encoding).streamwriter | |
| def iterencode(iterator, encoding, errors='strict', **kwargs): | |
| """ | |
| Encoding iterator. | |
| Encodes the input strings from the iterator using an IncrementalEncoder. | |
| errors and kwargs are passed through to the IncrementalEncoder | |
| constructor. | |
| """ | |
| encoder = getincrementalencoder(encoding)(errors, **kwargs) | |
| for input in iterator: | |
| output = encoder.encode(input) | |
| if output: | |
| yield output | |
| output = encoder.encode("", True) | |
| if output: | |
| yield output | |
| def iterdecode(iterator, encoding, errors='strict', **kwargs): | |
| """ | |
| Decoding iterator. | |
| Decodes the input strings from the iterator using an IncrementalDecoder. | |
| errors and kwargs are passed through to the IncrementalDecoder | |
| constructor. | |
| """ | |
| decoder = getincrementaldecoder(encoding)(errors, **kwargs) | |
| for input in iterator: | |
| output = decoder.decode(input) | |
| if output: | |
| yield output | |
| output = decoder.decode(b"", True) | |
| if output: | |
| yield output | |
| ### Helpers for charmap-based codecs | |
| def make_identity_dict(rng): | |
| """ make_identity_dict(rng) -> dict | |
| Return a dictionary where elements of the rng sequence are | |
| mapped to themselves. | |
| """ | |
| return {i:i for i in rng} | |
| def make_encoding_map(decoding_map): | |
| """ Creates an encoding map from a decoding map. | |
| If a target mapping in the decoding map occurs multiple | |
| times, then that target is mapped to None (undefined mapping), | |
| causing an exception when encountered by the charmap codec | |
| during translation. | |
| One example where this happens is cp875.py which decodes | |
| multiple character to \\u001a. | |
| """ | |
| m = {} | |
| for k,v in decoding_map.items(): | |
| if not v in m: | |
| m[v] = k | |
| else: | |
| m[v] = None | |
| return m | |
| ### error handlers | |
| try: | |
| strict_errors = lookup_error("strict") | |
| ignore_errors = lookup_error("ignore") | |
| replace_errors = lookup_error("replace") | |
| xmlcharrefreplace_errors = lookup_error("xmlcharrefreplace") | |
| backslashreplace_errors = lookup_error("backslashreplace") | |
| namereplace_errors = lookup_error("namereplace") | |
| except LookupError: | |
| # In --disable-unicode builds, these error handler are missing | |
| strict_errors = None | |
| ignore_errors = None | |
| replace_errors = None | |
| xmlcharrefreplace_errors = None | |
| backslashreplace_errors = None | |
| namereplace_errors = None | |
| # Tell modulefinder that using codecs probably needs the encodings | |
| # package | |
| _false = 0 | |
| if _false: | |
| import encodings | |
| ### Tests | |
| if __name__ == '__main__': | |
| # Make stdout translate Latin-1 output into UTF-8 output | |
| sys.stdout = EncodedFile(sys.stdout, 'latin-1', 'utf-8') | |
| # Have stdin translate Latin-1 input into UTF-8 input | |
| sys.stdin = EncodedFile(sys.stdin, 'utf-8', 'latin-1') |