18.1.4. email.mime: Creating email and MIME objects from scratch
Ordinarily, you get a message object structure by passing a file or some text to
a parser, which parses the text and returns the root message object. However
you can also build a complete message structure from scratch, or even individual
Message objects by hand. In fact, you can also take an
existing structure and add new Message objects, move them
around, etc. This makes a very convenient interface for slicing-and-dicing MIME
messages.
You can create a new object structure by creating Message
instances, adding attachments and all the appropriate headers manually. For MIME
messages though, the email package provides some convenient subclasses to
make things easier.
Here are the classes:
-
class
email.mime.base.MIMEBase(_maintype, _subtype, **_params)
Module: email.mime.base
This is the base class for all the MIME-specific subclasses of
Message. Ordinarily you won’t create instances
specifically of MIMEBase, although you could. MIMEBase
is provided primarily as a convenient base class for more specific
MIME-aware subclasses.
_maintype is the major type (e.g. text
or image), and _subtype is the minor
type (e.g. plain or gif). _params is a parameter
key/value dictionary and is passed directly to Message.add_header.
The MIMEBase class always adds a header
(based on _maintype, _subtype, and _params), and a
header (always set to 1.0).
-
class
email.mime.nonmultipart.MIMENonMultipart
Module: email.mime.nonmultipart
A subclass of MIMEBase, this is an intermediate base
class for MIME messages that are not multipart. The primary
purpose of this class is to prevent the use of the
attach() method, which only makes sense for
multipart messages. If attach()
is called, a MultipartConversionError exception is raised.
-
class
email.mime.multipart.MIMEMultipart([_subtype[, boundary[, _subparts[, _params]]]])
Module: email.mime.multipart
A subclass of MIMEBase, this is an intermediate base
class for MIME messages that are multipart. Optional _subtype
defaults to mixed, but can be used to specify the subtype of the
message. A header of multipart/_subtype
will be added to the message object. A header will
also be added.
Optional boundary is the multipart boundary string. When None (the
default), the boundary is calculated when needed (for example, when the
message is serialized).
_subparts is a sequence of initial subparts for the payload. It must be
possible to convert this sequence to a list. You can always attach new subparts
to the message by using the Message.attach method.
Additional parameters for the header are taken from
the keyword arguments, or passed into the _params argument, which is a keyword
dictionary.
-
class
email.mime.application.MIMEApplication(_data[, _subtype[, _encoder[, **_params]]])
Module: email.mime.application
A subclass of MIMENonMultipart, the
MIMEApplication class is used to represent MIME message objects of
major type application. _data is a string containing the raw
byte data. Optional _subtype specifies the MIME subtype and defaults to
octet-stream.
Optional _encoder is a callable (i.e. function) which will perform the actual
encoding of the data for transport. This callable takes one argument, which is
the MIMEApplication instance. It should use
get_payload() and
set_payload() to change the payload to encoded
form. It should also add
any or other headers to the message
object as necessary. The default encoding is base64. See the
email.encoders module for a list of the built-in encoders.
_params are passed straight through to the base class constructor.
-
class
email.mime.audio.MIMEAudio(_audiodata[, _subtype[, _encoder[, **_params]]])
Module: email.mime.audio
A subclass of MIMENonMultipart, the
MIMEAudio class is used to create MIME message objects of major type
audio. _audiodata is a string containing the raw audio data. If
this data can be decoded by the standard Python module sndhdr, then the
subtype will be automatically included in the header.
Otherwise you can explicitly specify the audio subtype via the _subtype
parameter. If the minor type could not be guessed and _subtype was not given,
then TypeError is raised.
Optional _encoder is a callable (i.e. function) which will perform the actual
encoding of the audio data for transport. This callable takes one argument,
which is the MIMEAudio instance. It should use
get_payload() and
set_payload() to change the payload to encoded
form. It should also add
any or other headers to the message
object as necessary. The default encoding is base64. See the
email.encoders module for a list of the built-in encoders.
_params are passed straight through to the base class constructor.
-
class
email.mime.image.MIMEImage(_imagedata[, _subtype[, _encoder[, **_params]]])
Module: email.mime.image
A subclass of MIMENonMultipart, the
MIMEImage class is used to create MIME message objects of major type
image. _imagedata is a string containing the raw image data. If
this data can be decoded by the standard Python module imghdr, then the
subtype will be automatically included in the header.
Otherwise you can explicitly specify the image subtype via the _subtype
parameter. If the minor type could not be guessed and _subtype was not given,
then TypeError is raised.
Optional _encoder is a callable (i.e. function) which will perform the actual
encoding of the image data for transport. This callable takes one argument,
which is the MIMEImage instance. It should use
get_payload() and
set_payload() to change the payload to encoded
form. It should also add
any or other headers to the message
object as necessary. The default encoding is base64. See the
email.encoders module for a list of the built-in encoders.
_params are passed straight through to the MIMEBase
constructor.
-
class
email.mime.message.MIMEMessage(_msg[, _subtype])
Module: email.mime.message
A subclass of MIMENonMultipart, the
MIMEMessage class is used to create MIME objects of main type
message. _msg is used as the payload, and must be an instance
of class Message (or a subclass thereof), otherwise
a TypeError is raised.
Optional _subtype sets the subtype of the message; it defaults to
rfc822.
-
class
email.mime.text.MIMEText(_text[, _subtype[, _charset]])
Module: email.mime.text
A subclass of MIMENonMultipart, the
MIMEText class is used to create MIME objects of major type
text. _text is the string for the payload. _subtype is the
minor type and defaults to plain. _charset is the character
set of the text and is passed as a parameter to the
MIMENonMultipart constructor; it defaults
to us-ascii. If _text is unicode, it is encoded using the
output_charset of _charset, otherwise it is used as-is.
Changed in version 2.4: The previously deprecated _encoding argument has been removed. Content
Transfer Encoding now happens implicitly based on the _charset
argument.
Unless the _charset parameter is explicitly set to None, the
MIMEText object created will have both a header
with a charset parameter, and a
header. This means that a subsequent set_payload call will not result
in an encoded payload, even if a charset is passed in the set_payload
command. You can “reset” this behavior by deleting the
Content-Transfer-Encoding header, after which a set_payload call
will automatically encode the new payload (and add a new
header).