diff options
Diffstat (limited to 'Doc/library/email.message.rst')
| -rw-r--r-- | Doc/library/email.message.rst | 78 |
1 files changed, 69 insertions, 9 deletions
diff --git a/Doc/library/email.message.rst b/Doc/library/email.message.rst index 2c7be8b..7a74220 100644 --- a/Doc/library/email.message.rst +++ b/Doc/library/email.message.rst @@ -31,19 +31,32 @@ parameters, and for recursively walking over the object tree. Here are the methods of the :class:`Message` class: -.. class:: Message() +.. class:: Message(policy=compat32) - The constructor takes no arguments. + The *policy* argument determiens the :mod:`~email.policy` that will be used + to update the message model. The default value, :class:`compat32 + <email.policy.Compat32>` maintains backward compatibility with the + Python 3.2 version of the email package. For more information see the + :mod:`~email.policy` documentation. + .. versionchanged:: 3.3 The *policy* keyword argument was added. - .. method:: as_string(unixfrom=False, maxheaderlen=0) + + .. method:: as_string(unixfrom=False, maxheaderlen=0, policy=None) Return the entire message flattened as a string. When optional *unixfrom* - is ``True``, the envelope header is included in the returned string. - *unixfrom* defaults to ``False``. Flattening the message may trigger - changes to the :class:`Message` if defaults need to be filled in to - complete the transformation to a string (for example, MIME boundaries may - be generated or modified). + is true, the envelope header is included in the returned string. + *unixfrom* defaults to ``False``. For backward compabitility reasons, + *maxheaderlen* defaults to ``0``, so if you want a different value you + must override it explicitly (the value specified for *max_line_length* in + the policy will be ignored by this method). The *policy* argument may be + used to override the default policy obtained from the message instance. + This can be used to control some of the formatting produced by the + method, since the specified *policy* will be passed to the ``Generator``. + + Flattening the message may trigger changes to the :class:`Message` if + defaults need to be filled in to complete the transformation to a string + (for example, MIME boundaries may be generated or modified). Note that this method is provided as a convenience and may not always format the message the way you want. For example, by default it does @@ -59,10 +72,57 @@ Here are the methods of the :class:`Message` class: g.flatten(msg) text = fp.getvalue() + If the message object contains binary data that is not encoded according + to RFC standards, the non-compliant data will be replaced by unicode + "unknown character" code points. (See also :meth:`.as_bytes` and + :class:`~email.generator.BytesGenerator`.) + + .. versionchanged:: 3.4 the *policy* keyword argument was added. + .. method:: __str__() - Equivalent to ``as_string(unixfrom=True)``. + Equivalent to :meth:`.as_string()`. Allows ``str(msg)`` to produce a + string containing the formatted message. + + + .. method:: as_bytes(unixfrom=False, policy=None) + + Return the entire message flattened as a bytes object. When optional + *unixfrom* is true, the envelope header is included in the returned + string. *unixfrom* defaults to ``False``. The *policy* argument may be + used to override the default policy obtained from the message instance. + This can be used to control some of the formatting produced by the + method, since the specified *policy* will be passed to the + ``BytesGenerator``. + + Flattening the message may trigger changes to the :class:`Message` if + defaults need to be filled in to complete the transformation to a string + (for example, MIME boundaries may be generated or modified). + + Note that this method is provided as a convenience and may not always + format the message the way you want. For example, by default it does + not do the mangling of lines that begin with ``From`` that is + required by the unix mbox format. For more flexibility, instantiate a + :class:`~email.generator.BytesGenerator` instance and use its + :meth:`flatten` method directly. For example:: + + from io import BytesIO + from email.generator import BytesGenerator + fp = BytesIO() + g = BytesGenerator(fp, mangle_from_=True, maxheaderlen=60) + g.flatten(msg) + text = fp.getvalue() + + .. versionadded:: 3.4 + + + .. method:: __bytes__() + + Equivalent to :meth:`.as_bytes()`. Allows ``bytes(msg)`` to produce a + bytes object containing the formatted message. + + .. versionadded:: 3.4 .. method:: is_multipart() |