Merged upstream changes.

This commit is contained in:
Vinay Sajip 2012-05-26 03:48:27 +01:00
commit b5267631cb
3 changed files with 110 additions and 1 deletions

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@ -558,6 +558,9 @@ in the `Porting Python code`_ section of this document.
New Email Package Features
==========================
Policy Framework
----------------
The email package now has a :mod:`~email.policy` framework. A
:class:`~email.policy.Policy` is an object with several methods and properties
that control how the email package behaves. The primary policy for Python 3.3
@ -610,6 +613,99 @@ policy instances for your different cases, and pass those in when you create
the ``generator``.
Provisional Policy with New Header API
--------------------------------------
While the policy framework is worthwhile all by itself, the main motivation for
introducing it is to allow the creation of new policies that implement new
features for the email package in a way that maintains backward compatibility
for those who do not use the new policies. Because the new policies introduce a
new API, we are releasing them in Python 3.3 as a :term:`provisional policy
<provisional package>`. Backwards incompatible changes (up to and including
removal of the code) may occur if deemed necessary by the core developers.
The new policies are instances of :class:`~email.policy.EmailPolicy`,
and add the following additional controls:
=============== =======================================================
refold_source Controls whether or not headers parsed by a
:mod:`~email.parser` are refolded by the
:mod:`~email.generator`. It can be ``none``, ``long``,
or ``all``. The default is ``long``, which means that
source headers with a line longer than
``max_line_length`` get refolded. ``none`` means no
line get refolded, and ``all`` means that all lines
get refolded.
header_factory A callable that take a ``name`` and ``value`` and
produces a custom header object.
=============== =======================================================
The ``header_factory`` is the key to the new features provided by the new
policies. When one of the new policies is used, any header retrieved from
a ``Message`` object is an object produced by the ``header_factory``, and any
time you set a header on a ``Message`` it becomes an object produced by
``header_factory``. All such header objects have a ``name`` attribute equal
to the header name. Address and Date headers have additional attributes
that give you access to the parsed data of the header. This means you can now
do things like this::
>>> m = Message(policy=SMTP)
>>> m['To'] = 'Éric <foo@example.com>'
>>> m['to']
'Éric <foo@example.com>'
>>> m['to'].addresses
(Address(display_name='Éric', username='foo', domain='example.com'),)
>>> m['to'].addresses[0].username
'foo'
>>> m['to'].addresses[0].display_name
'Éric'
>>> m['Date'] = email.utils.localtime()
>>> m['Date'].datetime
datetime.datetime(2012, 5, 25, 21, 39, 24, 465484, tzinfo=datetime.timezone(datetime.timedelta(-1, 72000), 'EDT'))
>>> m['Date']
'Fri, 25 May 2012 21:44:27 -0400'
>>> print(m)
To: =?utf-8?q?=C3=89ric?= <foo@example.com>
Date: Fri, 25 May 2012 21:44:27 -0400
You will note that the unicode display name is automatically encoded as
``utf-8`` when the message is serialized, but that when the header is accessed
directly, you get the unicode version. This eliminates any need to deal with
the :mod:`email.header` :meth:`~email.header.decode_header` or
:meth:`~email.header.make_header` functions.
You can also create addresses from parts::
>>> m['cc'] = [Group('pals', [Address('Bob', 'bob', 'example.com'),
... Address('Sally', 'sally', 'example.com')]),
... Address('Bonzo', addr_spec='bonz@laugh.com')]
>>> print(m)
To: =?utf-8?q?=C3=89ric?= <foo@example.com>
Date: Fri, 25 May 2012 21:44:27 -0400
cc: pals: Bob <bob@example.com>, Sally <sally@example.com>;, Bonzo <bonz@laugh.com>
Decoding to unicode is done automatically::
>>> m2 = message_from_string(str(m))
>>> m2['to']
'Éric <foo@example.com>'
When you parse a message, you can use the ``addresses`` and ``groups``
attributes of the header objects to access the groups and individual
addresses::
>>> m2['cc'].addresses
(Address(display_name='Bob', username='bob', domain='example.com'), Address(display_name='Sally', username='sally', domain='example.com'), Address(display_name='Bonzo', username='bonz', domain='laugh.com'))
>>> m2['cc'].groups
(Group(display_name='pals', addresses=(Address(display_name='Bob', username='bob', domain='example.com'), Address(display_name='Sally', username='sally', domain='example.com')), Group(display_name=None, addresses=(Address(display_name='Bonzo', username='bonz', domain='laugh.com'),))
In summary, if you use one of the new policies, header manipulation works the
way it ought to: your application works with unicode strings, and the email
package transparently encodes and decodes the unicode to and from the RFC
standard Content Transfer Encodings.
Other Language Changes
======================

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@ -707,7 +707,7 @@ def quote_plus(string, safe='', encoding=None, errors=None):
def quote_from_bytes(bs, safe='/'):
"""Like quote(), but accepts a bytes object rather than a str, and does
not perform string-to-bytes encoding. It always returns an ASCII string.
quote_from_bytes(b'abc def\xab') -> 'abc%20def%AB'
quote_from_bytes(b'abc def\x3f') -> 'abc%20def%3f'
"""
if not isinstance(bs, (bytes, bytearray)):
raise TypeError("quote_from_bytes() expected bytes")

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@ -10,6 +10,8 @@ What's New in Python 3.3.0 Alpha 4?
Core and Builtins
-----------------
- Issue #14712 (PEP 405): Virtual environments. Implemented by Vinay Sajip.
- Issue #14660 (PEP 420): Namespace packages. Implemented by Eric Smith.
- Issue #14494: Fix __future__.py and its documentation to note that
@ -44,6 +46,17 @@ Core and Builtins
Library
-------
- Issue #12586: Added new provisional policies that implement convenient
unicode support for email headers. See What's New for details.
- Issue #14731: Refactored email Policy framework to support full backward
compatibility with Python 3.2 by default yet allow for the introduction of
new features through new policies. Note that Policy.must_be_7bit is renamed
to cte_type.
- Issue #14920: Fix the help(urllib.parse) failure on locale C on terminals.
Have ascii characters in help.
- Issue #14548: Make multiprocessing finalizers check pid before
running to cope with possibility of gc running just after fork.