text: #! /usr/bin/python2.7
  """ Python Character Mapping Codec for ROT13.
  
      See http://ucsub.colorado.edu/~kominek/rot13/ for details.
  
      Written by Marc-Andre Lemburg (mal@lemburg.com).
  
  """#"
  
  import codecs
  
  ### Codec APIs
  
  class Codec(codecs.Codec):
  
      def encode(self,input,errors='strict'):
          return codecs.charmap_encode(input,errors,encoding_map)
  
      def decode(self,input,errors='strict'):
          return codecs.charmap_decode(input,errors,decoding_map)
  
  class IncrementalEncoder(codecs.IncrementalEncoder):
      def encode(self, input, final=False):
          return codecs.charmap_encode(input,self.errors,encoding_map)[0]
  
  class IncrementalDecoder(codecs.IncrementalDecoder):
      def decode(self, input, final=False):
          return codecs.charmap_decode(input,self.errors,decoding_map)[0]
  
  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,
      )
  
  ### Decoding Map
  
  decoding_map = codecs.make_identity_dict(range(256))
  decoding_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,
  })
  
  ### Encoding Map
  
  encoding_map = codecs.make_encoding_map(decoding_map)
  
  ### Filter API
  
  def rot13(infile, outfile):
      outfile.write(infile.read().encode('rot-13'))
  
  if __name__ == '__main__':
      import sys
      rot13(sys.stdin, sys.stdout)
  