JezK
Edit File: rot_13.py
#! /usr/bin/python3.2 """ Python Character Mapping Codec for ROT13. This codec de/encodes from str to str and is therefore usable with str.transform() and str.untransform(). Written by Marc-Andre Lemburg (mal@lemburg.com). """ import codecs ### Codec APIs class Codec(codecs.Codec): def encode(self, input, errors='strict'): return (input.translate(rot13_map), len(input)) def decode(self, input, errors='strict'): return (input.translate(rot13_map), len(input)) class IncrementalEncoder(codecs.IncrementalEncoder): def encode(self, input, final=False): return input.translate(rot13_map) class IncrementalDecoder(codecs.IncrementalDecoder): def decode(self, input, final=False): return input.translate(rot13_map) class StreamWriter(Codec,codecs.StreamWriter): pass class StreamReader(Codec,codecs.StreamReader): pass ### encodings module API def getregentry(): return codecs.CodecInfo( name='rot-13', encode=Codec().encode, decode=Codec().decode, incrementalencoder=IncrementalEncoder, incrementaldecoder=IncrementalDecoder, streamwriter=StreamWriter, streamreader=StreamReader, ) ### Map rot13_map = codecs.make_identity_dict(range(256)) rot13_map.update({ 0x0041: 0x004e, 0x0042: 0x004f, 0x0043: 0x0050, 0x0044: 0x0051, 0x0045: 0x0052, 0x0046: 0x0053, 0x0047: 0x0054, 0x0048: 0x0055, 0x0049: 0x0056, 0x004a: 0x0057, 0x004b: 0x0058, 0x004c: 0x0059, 0x004d: 0x005a, 0x004e: 0x0041, 0x004f: 0x0042, 0x0050: 0x0043, 0x0051: 0x0044, 0x0052: 0x0045, 0x0053: 0x0046, 0x0054: 0x0047, 0x0055: 0x0048, 0x0056: 0x0049, 0x0057: 0x004a, 0x0058: 0x004b, 0x0059: 0x004c, 0x005a: 0x004d, 0x0061: 0x006e, 0x0062: 0x006f, 0x0063: 0x0070, 0x0064: 0x0071, 0x0065: 0x0072, 0x0066: 0x0073, 0x0067: 0x0074, 0x0068: 0x0075, 0x0069: 0x0076, 0x006a: 0x0077, 0x006b: 0x0078, 0x006c: 0x0079, 0x006d: 0x007a, 0x006e: 0x0061, 0x006f: 0x0062, 0x0070: 0x0063, 0x0071: 0x0064, 0x0072: 0x0065, 0x0073: 0x0066, 0x0074: 0x0067, 0x0075: 0x0068, 0x0076: 0x0069, 0x0077: 0x006a, 0x0078: 0x006b, 0x0079: 0x006c, 0x007a: 0x006d, }) ### Filter API def rot13(infile, outfile): outfile.write(infile.read().encode('rot-13')) if __name__ == '__main__': import sys rot13(sys.stdin, sys.stdout)