/Lib/encodings/hex_codec.py

 1""" Python 'hex_codec' Codec - 2-digit hex content transfer encoding
 2
 3    Unlike most of the other codecs which target Unicode, this codec
 4    will return Python string objects for both encode and decode.
 5
 6    Written by Marc-Andre Lemburg (mal@lemburg.com).
 7
 8"""
 9import codecs, binascii
10
11### Codec APIs
12
13def hex_encode(input,errors='strict'):
14
15    """ Encodes the object input and returns a tuple (output
16        object, length consumed).
17
18        errors defines the error handling to apply. It defaults to
19        'strict' handling which is the only currently supported
20        error handling for this codec.
21
22    """
23    assert errors == 'strict'
24    output = binascii.b2a_hex(input)
25    return (output, len(input))
26
27def hex_decode(input,errors='strict'):
28
29    """ Decodes the object input and returns a tuple (output
30        object, length consumed).
31
32        input must be an object which provides the bf_getreadbuf
33        buffer slot. Python strings, buffer objects and memory
34        mapped files are examples of objects providing this slot.
35
36        errors defines the error handling to apply. It defaults to
37        'strict' handling which is the only currently supported
38        error handling for this codec.
39
40    """
41    assert errors == 'strict'
42    output = binascii.a2b_hex(input)
43    return (output, len(input))
44
45class Codec(codecs.Codec):
46
47    def encode(self, input,errors='strict'):
48        return hex_encode(input,errors)
49    def decode(self, input,errors='strict'):
50        return hex_decode(input,errors)
51
52class IncrementalEncoder(codecs.IncrementalEncoder):
53    def encode(self, input, final=False):
54        assert self.errors == 'strict'
55        return binascii.b2a_hex(input)
56
57class IncrementalDecoder(codecs.IncrementalDecoder):
58    def decode(self, input, final=False):
59        assert self.errors == 'strict'
60        return binascii.a2b_hex(input)
61
62class StreamWriter(Codec,codecs.StreamWriter):
63    pass
64
65class StreamReader(Codec,codecs.StreamReader):
66    pass
67
68### encodings module API
69
70def getregentry():
71    return codecs.CodecInfo(
72        name='hex',
73        encode=hex_encode,
74        decode=hex_decode,
75        incrementalencoder=IncrementalEncoder,
76        incrementaldecoder=IncrementalDecoder,
77        streamwriter=StreamWriter,
78        streamreader=StreamReader,
79    )