python zlibcodec codec zlib compression encoding this codec deencodes from bytes to bytes written by marcandre lemburg mallemburg com codec apis encodings module api this codec needs the optional zlib module codec apis encodings module api
import codecs
import zlib 



def zlib_encode(input, errors='strict'):
    assert errors == 'strict'
    return (zlib.compress(input), len(input))

def zlib_decode(input, errors='strict'):
    assert errors == 'strict'
    return (zlib.decompress(input), len(input))

class Codec(codecs.Codec):
    def encode(self, input, errors='strict'):
        return zlib_encode(input, errors)
    def decode(self, input, errors='strict'):
        return zlib_decode(input, errors)

class IncrementalEncoder(codecs.IncrementalEncoder):
    def __init__(self, errors='strict'):
        assert errors == 'strict'
        self.errors = errors
        self.compressobj = zlib.compressobj()

    def encode(self, input, final=False):
        if final:
            c = self.compressobj.compress(input)
            return c + self.compressobj.flush()
        else:
            return self.compressobj.compress(input)

    def reset(self):
        self.compressobj = zlib.compressobj()

class IncrementalDecoder(codecs.IncrementalDecoder):
    def __init__(self, errors='strict'):
        assert errors == 'strict'
        self.errors = errors
        self.decompressobj = zlib.decompressobj()

    def decode(self, input, final=False):
        if final:
            c = self.decompressobj.decompress(input)
            return c + self.decompressobj.flush()
        else:
            return self.decompressobj.decompress(input)

    def reset(self):
        self.decompressobj = zlib.decompressobj()

class StreamWriter(Codec, codecs.StreamWriter):
    charbuffertype = bytes

class StreamReader(Codec, codecs.StreamReader):
    charbuffertype = bytes



def getregentry():
    return codecs.CodecInfo(
        name='zlib',
        encode=zlib_encode,
        decode=zlib_decode,
        incrementalencoder=IncrementalEncoder,
        incrementaldecoder=IncrementalDecoder,
        streamreader=StreamReader,
        streamwriter=StreamWriter,
        _is_text_encoding=False,
    )