1 :mod:`email.encoders`: Encoders 2 ------------------------------- 3 4 .. module:: email.encoders 5 :synopsis: Encoders for email message payloads. 6 7 8 When creating :class:`~email.message.Message` objects from scratch, you often 9 need to encode the payloads for transport through compliant mail servers. This 10 is especially true for :mimetype:`image/\*` and :mimetype:`text/\*` type messages 11 containing binary data. 12 13 The :mod:`email` package provides some convenient encodings in its 14 :mod:`encoders` module. These encoders are actually used by the 15 :class:`~email.mime.audio.MIMEAudio` and :class:`~email.mime.image.MIMEImage` 16 class constructors to provide default encodings. All encoder functions take 17 exactly one argument, the message object to encode. They usually extract the 18 payload, encode it, and reset the payload to this newly encoded value. They 19 should also set the :mailheader:`Content-Transfer-Encoding` header as appropriate. 20 21 Note that these functions are not meaningful for a multipart message. They 22 must be applied to individual subparts instead, and will raise a 23 :exc:`TypeError` if passed a message whose type is multipart. 24 25 Here are the encoding functions provided: 26 27 28 .. function:: encode_quopri(msg) 29 30 Encodes the payload into quoted-printable form and sets the 31 :mailheader:`Content-Transfer-Encoding` header to ``quoted-printable`` [#]_. 32 This is a good encoding to use when most of your payload is normal printable 33 data, but contains a few unprintable characters. 34 35 36 .. function:: encode_base64(msg) 37 38 Encodes the payload into base64 form and sets the 39 :mailheader:`Content-Transfer-Encoding` header to ``base64``. This is a good 40 encoding to use when most of your payload is unprintable data since it is a more 41 compact form than quoted-printable. The drawback of base64 encoding is that it 42 renders the text non-human readable. 43 44 45 .. function:: encode_7or8bit(msg) 46 47 This doesn't actually modify the message's payload, but it does set the 48 :mailheader:`Content-Transfer-Encoding` header to either ``7bit`` or ``8bit`` as 49 appropriate, based on the payload data. 50 51 52 .. function:: encode_noop(msg) 53 54 This does nothing; it doesn't even set the 55 :mailheader:`Content-Transfer-Encoding` header. 56 57 .. rubric:: Footnotes 58 59 .. [#] Note that encoding with :meth:`encode_quopri` also encodes all tabs and space 60 characters in the data. 61 62
