| 1 """Encodings and related functions."""
6
7 __all__ = [
8 'encode_7or8bit',
9 'encode_base64',
10 'encode_noop',
11 'encode_quopri',
12 ]
13
14 import base64
15
16 from quopri import encodestring as _encodestring
17
18
19
20 def _qencode(s):
21 enc = _encodestring(s, quotetabs=True)
22 return enc.replace(' ', '=20')
24
25
26 def _bencode(s):
27 if not s:
30 return s
31 hasnewline = (s[-1] == '\n')
32 value = base64.encodestring(s)
33 if not hasnewline and value[-1] == '\n':
34 return value[:-1]
35 return value
36
37
38
39 def encode_base64(msg):
40 """Encode the message's payload in Base64.
41
42 Also, add an appropriate Content-Transfer-Encoding header.
43 """
44 orig = msg.get_payload()
45 encdata = _bencode(orig)
46 msg.set_payload(encdata)
47 msg['Content-Transfer-Encoding'] = 'base64'
48
49
50
51 def encode_quopri(msg):
52 """Encode the message's payload in quoted-printable.
53
54 Also, add an appropriate Content-Transfer-Encoding header.
55 """
56 orig = msg.get_payload()
57 encdata = _qencode(orig)
58 msg.set_payload(encdata)
59 msg['Content-Transfer-Encoding'] = 'quoted-printable'
60
61
62
63 def encode_7or8bit(msg):
64 """Set the Content-Transfer-Encoding header to 7bit or 8bit."""
65 orig = msg.get_payload()
66 if orig is None:
67 msg['Content-Transfer-Encoding'] = '7bit'
69 return
70 try:
73 orig.encode('ascii')
74 except UnicodeError:
75 charset = msg.get_charset()
77 output_cset = charset and charset.output_charset
78 if output_cset and output_cset.lower().startswith('iso-2202-'):
79 msg['Content-Transfer-Encoding'] = '7bit'
80 else:
81 msg['Content-Transfer-Encoding'] = '8bit'
82 else:
83 msg['Content-Transfer-Encoding'] = '7bit'
84
85
86
87 def encode_noop(msg):
88 """Do nothing."""
|