Personal Computer World 2009 February/PCWFEB09.iso/Software/Linux/Kubuntu 8.10/kubuntu-8.10-desktop-i386.iso/casper/filesystem.squashfs/usr/lib/python2.5/codecs.pyc

Python Compiled Bytecode | 2008-10-29 | 33.1 KB | 1,025 lines

# Source Generated with Decompyle++
# File: in.pyc (Python 2.5)

''' codecs -- Python Codec Registry, API and helpers.


Written by Marc-Andre Lemburg ([e-mail]).

(c) Copyright CNRI, All Rights Reserved. NO WARRANTY.

'''
import __builtin__
import sys

try:
    from _codecs import *
except ImportError:
    why = None
    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',
    'strict_errors',
    'ignore_errors',
    'replace_errors',
    'xmlcharrefreplace_errors',
    'register_error',
    'lookup_error']
BOM_UTF8 = '\xef\xbb\xbf'
BOM_LE = BOM_UTF16_LE = '\xff\xfe'
BOM_BE = BOM_UTF16_BE = '\xfe\xff'
BOM_UTF32_LE = '\xff\xfe\x00\x00'
BOM_UTF32_BE = '\x00\x00\xfe\xff'
if sys.byteorder == 'little':
    BOM = BOM_UTF16 = BOM_UTF16_LE
    BOM_UTF32 = BOM_UTF32_LE
else:
    BOM = BOM_UTF16 = BOM_UTF16_BE
    BOM_UTF32 = BOM_UTF32_BE
BOM32_LE = BOM_UTF16_LE
BOM32_BE = BOM_UTF16_BE
BOM64_LE = BOM_UTF32_LE
BOM64_BE = BOM_UTF32_BE

class CodecInfo(tuple):

    def __new__(cls, encode, decode, streamreader = None, streamwriter = None, incrementalencoder = None, incrementaldecoder = None, name = 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
        return self


    def __repr__(self):
        return '<%s.%s object for encoding %s at 0x%x>' % (self.__class__.__module__, self.__class__.__name__, 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.
         'xmlcharrefreplace' - Replace with the appropriate XML
                               character reference (only for encoding).
         'backslashreplace'  - Replace with backslashed 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
            StreamCodec for codecs which have to keep state in order to
            make encoding/decoding 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
            StreamCodec for codecs which have to keep state in order to
            make encoding/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.
        '''
        pass



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)
        self.buffer = ''


    def _buffer_encode(self, input, errors, final):
        raise NotImplementedError


    def encode(self, input, final = False):
        data = self.buffer + input
        (result, consumed) = self._buffer_encode(data, self.errors, final)
        self.buffer = data[consumed:]
        return result


    def reset(self):
        IncrementalEncoder.reset(self)
        self.buffer = ''



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'):
        '''
        Creates a 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):
        '''
        Decodes input and returns the resulting object.
        '''
        raise NotImplementedError


    def reset(self):
        '''
        Resets the decoder to the initial state.
        '''
        pass



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)
        self.buffer = ''


    def _buffer_decode(self, input, errors, final):
        raise NotImplementedError


    def decode(self, input, final = False):
        data = self.buffer + input
        (result, consumed) = self._buffer_decode(data, self.errors, final)
        self.buffer = data[consumed:]
        return result


    def reset(self):
        IncrementalDecoder.reset(self)
        self.buffer = ''



class StreamWriter(Codec):

    def __init__(self, stream, errors = 'strict'):
        """ Creates a StreamWriter instance.

            stream must be a file-like object open for writing
            (binary) data.

            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 (only for encoding).

            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 __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):

    def __init__(self, stream, errors = 'strict'):
        """ Creates a StreamReader instance.

            stream must be a file-like object open for reading
            (binary) data.

            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;

            The set of allowed parameter values can be extended via
            register_error.
        """
        self.stream = stream
        self.errors = errors
        self.bytebuffer = ''
        self.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 characters to read from the
            stream. read() will never return more than chars
            characters, but it might return less, if there are not enough
            characters available.

            size indicates the approximate maximum number of bytes to
            read from the stream for decoding purposes. 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 self.linebuffer:
            self.charbuffer = ''.join(self.linebuffer)
            self.linebuffer = None

        while True:
            if chars < 0:
                if size < 0:
                    if self.charbuffer:
                        break

                elif len(self.charbuffer) >= size:
                    break

            elif len(self.charbuffer) >= chars:
                break

            if size < 0:
                newdata = self.stream.read()
            else:
                newdata = self.stream.read(size)
            data = self.bytebuffer + newdata

            try:
                (newchars, decodedbytes) = self.decode(data, self.errors)
            except UnicodeDecodeError:
                exc = None
                if firstline:
                    (newchars, decodedbytes) = self.decode(data[:exc.start], self.errors)
                    lines = newchars.splitlines(True)
                    if len(lines) <= 1:
                        raise

                else:
                    raise
            except:
                firstline

            self.bytebuffer = data[decodedbytes:]
            self.charbuffer += newchars
            if not newdata:
                break
                continue
            self
        if chars < 0:
            result = self.charbuffer
            self.charbuffer = ''
        else:
            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 self.linebuffer:
            line = self.linebuffer[0]
            del self.linebuffer[0]
            if len(self.linebuffer) == 1:
                self.charbuffer = self.linebuffer[0]
                self.linebuffer = None

            if not keepends:
                line = line.splitlines(False)[0]

            return line

        if not size:
            pass
        readsize = 72
        line = ''
        while True:
            data = self.read(readsize, firstline = True)
            if data:
                if data.endswith('\r'):
                    data += self.read(size = 1, chars = 1)


            line += data
            lines = line.splitlines(True)
            if lines:
                if len(lines) > 1:
                    line = lines[0]
                    del lines[0]
                    if len(lines) > 1:
                        lines[-1] += self.charbuffer
                        self.linebuffer = lines
                        self.charbuffer = None
                    else:
                        self.charbuffer = lines[0] + self.charbuffer
                    if not keepends:
                        line = line.splitlines(False)[0]

                    break

                line0withend = lines[0]
                line0withoutend = lines[0].splitlines(False)[0]
                if line0withend != line0withoutend:
                    self.charbuffer = ''.join(lines[1:]) + self.charbuffer
                    if keepends:
                        line = line0withend
                    else:
                        line = line0withoutend
                    break


            if not data or size is not None:
                if line and not keepends:
                    line = line.splitlines(False)[0]

                break

            if readsize < 8000:
                readsize *= 2
                continue
        return line


    def readlines(self, sizehint = None, keepends = True):
        """ Read all lines available on the input stream
            and return them as list of lines.

            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 = ''
        self.charbuffer = u''
        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.reset()
        self.stream.seek(offset, whence)


    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.

    '''
    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 self.reader.next()


    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 __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 StreamRecoder:
    ''' StreamRecoder instances provide a frontend - backend
        view of encoding data.

        They use the complete set of APIs returned by the
        codecs.lookup() function to implement their task.

        Data written to the stream is first decoded into an
        intermediate format (which is dependent on the given codec
        combination) and then written to the stream using an instance
        of the provided Writer class.

        In the other direction, data is read from the stream using a
        Reader instance and then return encoded data to the caller.

    '''
    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
            input to .read() and output of .write()) while
            Reader and Writer work on the backend (reading and
            writing to the stream).

            You can use these objects to do transparent direct
            recodings from e.g. latin-1 to utf-8 and back.

            stream must be a file-like object.

            encode, decode must adhere to the Codec interface, Reader,
            Writer must be factory functions or classes providing the
            StreamReader, StreamWriter interface resp.

            encode and decode are needed for the frontend translation,
            Reader and Writer for the backend translation. Unicode is
            used as intermediate encoding.

            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(1)


    def next(self):
        ''' Return the next decoded line from the input stream.'''
        data = self.reader.next()
        (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 = ''.join(list)
        (data, bytesdecoded) = self.decode(data, self.errors)
        return self.writer.write(data)


    def reset(self):
        self.reader.reset()
        self.writer.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()



def open(filename, mode = 'rb', 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.

        Files are always opened in binary mode, even if no binary mode
        was specified. This is done to avoid data loss due to encodings
        using 8-bit values. The default file mode is 'rb' meaning to
        open the file in binary 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 line buffered.

        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:
        mode = mode + 'b'

    file = __builtin__.open(filename, mode, buffering)
    if encoding is None:
        return file

    info = lookup(encoding)
    srw = StreamReaderWriter(file, info.streamreader, info.streamwriter, errors)
    srw.encoding = encoding
    return srw


def EncodedFile(file, data_encoding, file_encoding = None, errors = 'strict'):
    """ Return a wrapped version of file which provides transparent
        encoding translation.

        Strings written to the wrapped file are interpreted according
        to the given data_encoding and then written to the original
        file as string using file_encoding. The intermediate encoding
        will usually be Unicode but depends on the specified codecs.

        Strings are read from the file using file_encoding and then
        passed back to the caller as string 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)
    sr.data_encoding = data_encoding
    sr.file_encoding = file_encoding
    return sr


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 a 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
            continue

    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 a 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
            continue

    output = decoder.decode('', True)
    if output:
        yield output



def make_identity_dict(rng):
    ''' make_identity_dict(rng) -> dict

        Return a dictionary where elements of the rng sequence are
        mapped to themselves.

    '''
    res = { }
    for i in rng:
        res[i] = i

    return res


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 v not in m:
            m[v] = k
            continue
        m[v] = None

    return m


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')
except LookupError:
    strict_errors = None
    ignore_errors = None
    replace_errors = None
    xmlcharrefreplace_errors = None
    backslashreplace_errors = None

_false = 0
if _false:
    import encodings

if __name__ == '__main__':
    sys.stdout = EncodedFile(sys.stdout, 'latin-1', 'utf-8')
    sys.stdin = EncodedFile(sys.stdin, 'utf-8', 'latin-1')