Python codecs 模块，make_encoding_map() 实例源码

def _256_exception_codec(name,exceptions,rexceptions,baseRange=range(32,256)):
        import codecs
        decoding_map = codecs.make_identity_dict(baseRange)
        decoding_map.update(exceptions)
        encoding_map = codecs.make_encoding_map(decoding_map)
        if rexceptions: encoding_map.update(rexceptions)
        ### Codec APIs
        class Codec(codecs.Codec):
            def encode(self,input,errors='strict',charmap_encode=codecs.charmap_encode,encoding_map=encoding_map):
                return charmap_encode(input,errors,encoding_map)

            def decode(self,input,errors='strict',charmap_decode=codecs.charmap_decode,decoding_map=decoding_map):
                return charmap_decode(input,errors,decoding_map)

        class StreamWriter(Codec,codecs.StreamWriter):
            pass

        class StreamReader(Codec,codecs.StreamReader):
            pass
        C = Codec()
        return codecs.CodecInfo(C.encode,C.decode,streamreader=StreamReader,streamwriter=StreamWriter,name=name)