jpayne@69: #!/usr/bin/env python
jpayne@69: """ Python Character Mapping Codec for ROT13.
jpayne@69: 
jpayne@69: This codec de/encodes from str to str.
jpayne@69: 
jpayne@69: Written by Marc-Andre Lemburg (mal@lemburg.com).
jpayne@69: """
jpayne@69: 
jpayne@69: import codecs
jpayne@69: 
jpayne@69: ### Codec APIs
jpayne@69: 
jpayne@69: class Codec(codecs.Codec):
jpayne@69:     def encode(self, input, errors='strict'):
jpayne@69:         return (str.translate(input, rot13_map), len(input))
jpayne@69: 
jpayne@69:     def decode(self, input, errors='strict'):
jpayne@69:         return (str.translate(input, rot13_map), len(input))
jpayne@69: 
jpayne@69: class IncrementalEncoder(codecs.IncrementalEncoder):
jpayne@69:     def encode(self, input, final=False):
jpayne@69:         return str.translate(input, rot13_map)
jpayne@69: 
jpayne@69: class IncrementalDecoder(codecs.IncrementalDecoder):
jpayne@69:     def decode(self, input, final=False):
jpayne@69:         return str.translate(input, rot13_map)
jpayne@69: 
jpayne@69: class StreamWriter(Codec,codecs.StreamWriter):
jpayne@69:     pass
jpayne@69: 
jpayne@69: class StreamReader(Codec,codecs.StreamReader):
jpayne@69:     pass
jpayne@69: 
jpayne@69: ### encodings module API
jpayne@69: 
jpayne@69: def getregentry():
jpayne@69:     return codecs.CodecInfo(
jpayne@69:         name='rot-13',
jpayne@69:         encode=Codec().encode,
jpayne@69:         decode=Codec().decode,
jpayne@69:         incrementalencoder=IncrementalEncoder,
jpayne@69:         incrementaldecoder=IncrementalDecoder,
jpayne@69:         streamwriter=StreamWriter,
jpayne@69:         streamreader=StreamReader,
jpayne@69:         _is_text_encoding=False,
jpayne@69:     )
jpayne@69: 
jpayne@69: ### Map
jpayne@69: 
jpayne@69: rot13_map = codecs.make_identity_dict(range(256))
jpayne@69: rot13_map.update({
jpayne@69:    0x0041: 0x004e,
jpayne@69:    0x0042: 0x004f,
jpayne@69:    0x0043: 0x0050,
jpayne@69:    0x0044: 0x0051,
jpayne@69:    0x0045: 0x0052,
jpayne@69:    0x0046: 0x0053,
jpayne@69:    0x0047: 0x0054,
jpayne@69:    0x0048: 0x0055,
jpayne@69:    0x0049: 0x0056,
jpayne@69:    0x004a: 0x0057,
jpayne@69:    0x004b: 0x0058,
jpayne@69:    0x004c: 0x0059,
jpayne@69:    0x004d: 0x005a,
jpayne@69:    0x004e: 0x0041,
jpayne@69:    0x004f: 0x0042,
jpayne@69:    0x0050: 0x0043,
jpayne@69:    0x0051: 0x0044,
jpayne@69:    0x0052: 0x0045,
jpayne@69:    0x0053: 0x0046,
jpayne@69:    0x0054: 0x0047,
jpayne@69:    0x0055: 0x0048,
jpayne@69:    0x0056: 0x0049,
jpayne@69:    0x0057: 0x004a,
jpayne@69:    0x0058: 0x004b,
jpayne@69:    0x0059: 0x004c,
jpayne@69:    0x005a: 0x004d,
jpayne@69:    0x0061: 0x006e,
jpayne@69:    0x0062: 0x006f,
jpayne@69:    0x0063: 0x0070,
jpayne@69:    0x0064: 0x0071,
jpayne@69:    0x0065: 0x0072,
jpayne@69:    0x0066: 0x0073,
jpayne@69:    0x0067: 0x0074,
jpayne@69:    0x0068: 0x0075,
jpayne@69:    0x0069: 0x0076,
jpayne@69:    0x006a: 0x0077,
jpayne@69:    0x006b: 0x0078,
jpayne@69:    0x006c: 0x0079,
jpayne@69:    0x006d: 0x007a,
jpayne@69:    0x006e: 0x0061,
jpayne@69:    0x006f: 0x0062,
jpayne@69:    0x0070: 0x0063,
jpayne@69:    0x0071: 0x0064,
jpayne@69:    0x0072: 0x0065,
jpayne@69:    0x0073: 0x0066,
jpayne@69:    0x0074: 0x0067,
jpayne@69:    0x0075: 0x0068,
jpayne@69:    0x0076: 0x0069,
jpayne@69:    0x0077: 0x006a,
jpayne@69:    0x0078: 0x006b,
jpayne@69:    0x0079: 0x006c,
jpayne@69:    0x007a: 0x006d,
jpayne@69: })
jpayne@69: 
jpayne@69: ### Filter API
jpayne@69: 
jpayne@69: def rot13(infile, outfile):
jpayne@69:     outfile.write(codecs.encode(infile.read(), 'rot-13'))
jpayne@69: 
jpayne@69: if __name__ == '__main__':
jpayne@69:     import sys
jpayne@69:     rot13(sys.stdin, sys.stdout)