cpython/Doc/library/email.mime.rst
2007-08-15 14:28:22 +00:00

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:mod:`email`: Creating email and MIME objects from scratch
----------------------------------------------------------
.. module:: email.mime
:synopsis: Build MIME messages.
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
:class:`Message` objects by hand. In fact, you can also take an existing
structure and add new :class:`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 :class:`Message` instances,
adding attachments and all the appropriate headers manually. For MIME messages
though, the :mod:`email` package provides some convenient subclasses to make
things easier.
Here are the classes:
.. class:: MIMEBase(_maintype, _subtype, **_params)
Module: :mod:`email.mime.base`
This is the base class for all the MIME-specific subclasses of :class:`Message`.
Ordinarily you won't create instances specifically of :class:`MIMEBase`,
although you could. :class:`MIMEBase` is provided primarily as a convenient
base class for more specific MIME-aware subclasses.
*_maintype* is the :mailheader:`Content-Type` major type (e.g. :mimetype:`text`
or :mimetype:`image`), and *_subtype* is the :mailheader:`Content-Type` minor
type (e.g. :mimetype:`plain` or :mimetype:`gif`). *_params* is a parameter
key/value dictionary and is passed directly to :meth:`Message.add_header`.
The :class:`MIMEBase` class always adds a :mailheader:`Content-Type` header
(based on *_maintype*, *_subtype*, and *_params*), and a
:mailheader:`MIME-Version` header (always set to ``1.0``).
.. class:: MIMENonMultipart()
Module: :mod:`email.mime.nonmultipart`
A subclass of :class:`MIMEBase`, this is an intermediate base class for MIME
messages that are not :mimetype:`multipart`. The primary purpose of this class
is to prevent the use of the :meth:`attach` method, which only makes sense for
:mimetype:`multipart` messages. If :meth:`attach` is called, a
:exc:`MultipartConversionError` exception is raised.
.. versionadded:: 2.2.2
.. class:: MIMEMultipart([subtype[, boundary[, _subparts[, _params]]]])
Module: :mod:`email.mime.multipart`
A subclass of :class:`MIMEBase`, this is an intermediate base class for MIME
messages that are :mimetype:`multipart`. Optional *_subtype* defaults to
:mimetype:`mixed`, but can be used to specify the subtype of the message. A
:mailheader:`Content-Type` header of :mimetype:`multipart/`*_subtype* will be
added to the message object. A :mailheader:`MIME-Version` header will also be
added.
Optional *boundary* is the multipart boundary string. When ``None`` (the
default), the boundary is calculated when needed.
*_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 :meth:`Message.attach` method.
Additional parameters for the :mailheader:`Content-Type` header are taken from
the keyword arguments, or passed into the *_params* argument, which is a keyword
dictionary.
.. versionadded:: 2.2.2
.. class:: MIMEApplication(_data[, _subtype[, _encoder[, **_params]]])
Module: :mod:`email.mime.application`
A subclass of :class:`MIMENonMultipart`, the :class:`MIMEApplication` class is
used to represent MIME message objects of major type :mimetype:`application`.
*_data* is a string containing the raw byte data. Optional *_subtype* specifies
the MIME subtype and defaults to :mimetype:`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 :class:`MIMEApplication` instance. It should use :meth:`get_payload` and
:meth:`set_payload` to change the payload to encoded form. It should also add
any :mailheader:`Content-Transfer-Encoding` or other headers to the message
object as necessary. The default encoding is base64. See the
:mod:`email.encoders` module for a list of the built-in encoders.
*_params* are passed straight through to the base class constructor.
.. versionadded:: 2.5
.. class:: MIMEAudio(_audiodata[, _subtype[, _encoder[, **_params]]])
Module: :mod:`email.mime.audio`
A subclass of :class:`MIMENonMultipart`, the :class:`MIMEAudio` class is used to
create MIME message objects of major type :mimetype:`audio`. *_audiodata* is a
string containing the raw audio data. If this data can be decoded by the
standard Python module :mod:`sndhdr`, then the subtype will be automatically
included in the :mailheader:`Content-Type` 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 :exc:`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 :class:`MIMEAudio` instance. It should use :meth:`get_payload` and
:meth:`set_payload` to change the payload to encoded form. It should also add
any :mailheader:`Content-Transfer-Encoding` or other headers to the message
object as necessary. The default encoding is base64. See the
:mod:`email.encoders` module for a list of the built-in encoders.
*_params* are passed straight through to the base class constructor.
.. class:: MIMEImage(_imagedata[, _subtype[, _encoder[, **_params]]])
Module: :mod:`email.mime.image`
A subclass of :class:`MIMENonMultipart`, the :class:`MIMEImage` class is used to
create MIME message objects of major type :mimetype:`image`. *_imagedata* is a
string containing the raw image data. If this data can be decoded by the
standard Python module :mod:`imghdr`, then the subtype will be automatically
included in the :mailheader:`Content-Type` 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 :exc:`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 :class:`MIMEImage` instance. It should use :meth:`get_payload` and
:meth:`set_payload` to change the payload to encoded form. It should also add
any :mailheader:`Content-Transfer-Encoding` or other headers to the message
object as necessary. The default encoding is base64. See the
:mod:`email.encoders` module for a list of the built-in encoders.
*_params* are passed straight through to the :class:`MIMEBase` constructor.
.. class:: MIMEMessage(_msg[, _subtype])
Module: :mod:`email.mime.message`
A subclass of :class:`MIMENonMultipart`, the :class:`MIMEMessage` class is used
to create MIME objects of main type :mimetype:`message`. *_msg* is used as the
payload, and must be an instance of class :class:`Message` (or a subclass
thereof), otherwise a :exc:`TypeError` is raised.
Optional *_subtype* sets the subtype of the message; it defaults to
:mimetype:`rfc822`.
.. class:: MIMEText(_text[, _subtype[, _charset]])
Module: :mod:`email.mime.text`
A subclass of :class:`MIMENonMultipart`, the :class:`MIMEText` class is used to
create MIME objects of major type :mimetype:`text`. *_text* is the string for
the payload. *_subtype* is the minor type and defaults to :mimetype:`plain`.
*_charset* is the character set of the text and is passed as a parameter to the
:class:`MIMENonMultipart` constructor; it defaults to ``us-ascii``. No guessing
or encoding is performed on the text data.
.. versionchanged:: 2.4
The previously deprecated *_encoding* argument has been removed. Encoding
happens implicitly based on the *_charset* argument.