[Python-checkins] cpython: #20476: add a message_factory policy attribute to email.
r.david.murray
python-checkins at python.org
Fri Sep 9 18:40:33 EDT 2016
https://hg.python.org/cpython/rev/9ba8f4be0651
changeset: 103489:9ba8f4be0651
user: R David Murray <rdmurray at bitdance.com>
date: Fri Sep 09 18:39:18 2016 -0400
summary:
#20476: add a message_factory policy attribute to email.
files:
Doc/library/email.parser.rst | 20 ++-
Doc/library/email.policy.rst | 11 ++
Doc/whatsnew/3.6.rst | 7 +
Lib/email/_policybase.py | 4 +
Lib/email/feedparser.py | 9 +-
Lib/email/message.py | 8 +-
Lib/email/policy.py | 2 +
Lib/test/test_email/test_parser.py | 91 ++++++++++++-----
Lib/test/test_email/test_policy.py | 42 ++++---
9 files changed, 128 insertions(+), 66 deletions(-)
diff --git a/Doc/library/email.parser.rst b/Doc/library/email.parser.rst
--- a/Doc/library/email.parser.rst
+++ b/Doc/library/email.parser.rst
@@ -73,8 +73,9 @@
.. class:: BytesFeedParser(_factory=None, *, policy=policy.compat32)
Create a :class:`BytesFeedParser` instance. Optional *_factory* is a
- no-argument callable; if not specified determine the default based on the
- *policy*. Call *_factory* whenever a new message object is needed.
+ no-argument callable; if not specified use the
+ :attr:`~email.policy.Policy.message_factory` from the *policy*. Call
+ *_factory* whenever a new message object is needed.
If *policy* is specified use the rules it specifies to update the
representation of the message. If *policy* is not set, use the
@@ -91,6 +92,7 @@
.. versionadded:: 3.2
.. versionchanged:: 3.3 Added the *policy* keyword.
+ .. versionchanged:: 3.6 _factory defaults to the policy ``message_factory``.
.. method:: feed(data)
@@ -146,6 +148,7 @@
.. versionchanged:: 3.3
Removed the *strict* argument that was deprecated in 2.4. Added the
*policy* keyword.
+ .. versionchanged:: 3.6 _class defaults to the policy ``message_factory``.
.. method:: parse(fp, headersonly=False)
@@ -194,6 +197,7 @@
.. versionchanged:: 3.3
Removed the *strict* argument. Added the *policy* keyword.
+ .. versionchanged:: 3.6 _class defaults to the policy ``message_factory``.
.. method:: parse(fp, headersonly=False)
@@ -230,8 +234,7 @@
.. currentmodule:: email
-.. function:: message_from_bytes(s, _class=None, *, \
- policy=policy.compat32)
+.. function:: message_from_bytes(s, _class=None, *, policy=policy.compat32)
Return a message object structure from a :term:`bytes-like object`. This is
equivalent to ``BytesParser().parsebytes(s)``. Optional *_class* and
@@ -243,7 +246,7 @@
Removed the *strict* argument. Added the *policy* keyword.
-.. function:: message_from_binary_file(fp, _class=None, *, \
+.. function:: message_from_binary_file(fp, _class=None, *,
policy=policy.compat32)
Return a message object structure tree from an open binary :term:`file
@@ -256,8 +259,7 @@
Removed the *strict* argument. Added the *policy* keyword.
-.. function:: message_from_string(s, _class=None, *, \
- policy=policy.compat32)
+.. function:: message_from_string(s, _class=None, *, policy=policy.compat32)
Return a message object structure from a string. This is equivalent to
``Parser().parsestr(s)``. *_class* and *policy* are interpreted as
@@ -267,8 +269,7 @@
Removed the *strict* argument. Added the *policy* keyword.
-.. function:: message_from_file(fp, _class=None, *, \
- policy=policy.compat32)
+.. function:: message_from_file(fp, _class=None, *, policy=policy.compat32)
Return a message object structure tree from an open :term:`file object`.
This is equivalent to ``Parser().parse(fp)``. *_class* and *policy* are
@@ -276,6 +277,7 @@
.. versionchanged:: 3.3
Removed the *strict* argument. Added the *policy* keyword.
+ .. versionchanged:: 3.6 _class defaults to the policy ``message_factory``.
Here's an example of how you might use :func:`message_from_bytes` at an
diff --git a/Doc/library/email.policy.rst b/Doc/library/email.policy.rst
--- a/Doc/library/email.policy.rst
+++ b/Doc/library/email.policy.rst
@@ -221,6 +221,14 @@
The *mangle_from_* parameter.
+ .. attribute:: message_factory
+
+ A factory function for constructing a new empty message object. Used
+ by the parser when building messages. Defaults to
+ :class:`~email.message.Message`.
+
+ .. versionadded:: 3.6
+
The following :class:`Policy` method is intended to be called by code using
the email library to create policy instances with custom settings:
@@ -368,6 +376,9 @@
on the type of the field. The parsing and folding algorithm fully implement
:rfc:`2047` and :rfc:`5322`.
+ The default value for the :attr:`~email.policy.Policy.message_factory`
+ attribute is :class:`~email.message.EmailMessage`.
+
In addition to the settable attributes listed above that apply to all
policies, this policy adds the following additional attributes:
diff --git a/Doc/whatsnew/3.6.rst b/Doc/whatsnew/3.6.rst
--- a/Doc/whatsnew/3.6.rst
+++ b/Doc/whatsnew/3.6.rst
@@ -598,6 +598,13 @@
The :class:`~email.generator.DecodedGenerator` now supports the *policy*
keyword.
+There is a new :mod:`~email.policy` attribute,
+:attr:`~email.policy.Policy.message_factory`, that controls what class is used
+by default when the parser creates new message objects. For the
+:attr:`email.policy.compat32` policy this is :class:`~email.message.Message`,
+for the new policies it is :class:`~email.message.EmailMessage`.
+(Contributed by R. David Murray in :issue:`20476`.)
+
encodings
---------
diff --git a/Lib/email/_policybase.py b/Lib/email/_policybase.py
--- a/Lib/email/_policybase.py
+++ b/Lib/email/_policybase.py
@@ -154,6 +154,8 @@
them. This is used when the message is being
serialized by a generator. Default: True.
+ message_factory -- the class to use to create new message objects.
+
"""
raise_on_defect = False
@@ -161,6 +163,8 @@
cte_type = '8bit'
max_line_length = 78
mangle_from_ = False
+ # XXX To avoid circular imports, this is set in email.message.
+ message_factory = None
def handle_defect(self, obj, defect):
"""Based on policy, either raise defect or call register_defect.
diff --git a/Lib/email/feedparser.py b/Lib/email/feedparser.py
--- a/Lib/email/feedparser.py
+++ b/Lib/email/feedparser.py
@@ -24,7 +24,6 @@
import re
from email import errors
-from email import message
from email._policybase import compat32
from collections import deque
from io import StringIO
@@ -148,13 +147,7 @@
self.policy = policy
self._old_style_factory = False
if _factory is None:
- # What this should be:
- #self._factory = policy.default_message_factory
- # but, because we are post 3.4 feature freeze, fix with temp hack:
- if self.policy is compat32:
- self._factory = message.Message
- else:
- self._factory = message.EmailMessage
+ self._factory = policy.message_factory
else:
self._factory = _factory
try:
diff --git a/Lib/email/message.py b/Lib/email/message.py
--- a/Lib/email/message.py
+++ b/Lib/email/message.py
@@ -4,18 +4,17 @@
"""Basic message object for the email package object model."""
-__all__ = ['Message']
+__all__ = ['Message', 'EmailMessage']
import re
import uu
import quopri
-import warnings
from io import BytesIO, StringIO
# Intrapackage imports
from email import utils
from email import errors
-from email._policybase import compat32
+from email._policybase import Policy, compat32
from email import charset as _charset
from email._encoded_words import decode_b
Charset = _charset.Charset
@@ -1163,3 +1162,6 @@
super().set_content(*args, **kw)
if 'MIME-Version' not in self:
self['MIME-Version'] = '1.0'
+
+# Set message_factory on Policy here to avoid a circular import.
+Policy.message_factory = Message
diff --git a/Lib/email/policy.py b/Lib/email/policy.py
--- a/Lib/email/policy.py
+++ b/Lib/email/policy.py
@@ -7,6 +7,7 @@
from email.utils import _has_surrogates
from email.headerregistry import HeaderRegistry as HeaderRegistry
from email.contentmanager import raw_data_manager
+from email.message import EmailMessage
__all__ = [
'Compat32',
@@ -82,6 +83,7 @@
"""
+ message_factory = EmailMessage
utf8 = False
refold_source = 'long'
header_factory = HeaderRegistry()
diff --git a/Lib/test/test_email/test_parser.py b/Lib/test/test_email/test_parser.py
--- a/Lib/test/test_email/test_parser.py
+++ b/Lib/test/test_email/test_parser.py
@@ -1,7 +1,7 @@
import io
import email
import unittest
-from email.message import Message
+from email.message import Message, EmailMessage
from email.policy import default
from test.test_email import TestEmailBase
@@ -39,38 +39,71 @@
# The unicode line splitter splits on unicode linebreaks, which are
# more numerous than allowed by the email RFCs; make sure we are only
# splitting on those two.
- msg = self.parser(
- "Next-Line: not\x85broken\r\n"
- "Null: not\x00broken\r\n"
- "Vertical-Tab: not\vbroken\r\n"
- "Form-Feed: not\fbroken\r\n"
- "File-Separator: not\x1Cbroken\r\n"
- "Group-Separator: not\x1Dbroken\r\n"
- "Record-Separator: not\x1Ebroken\r\n"
- "Line-Separator: not\u2028broken\r\n"
- "Paragraph-Separator: not\u2029broken\r\n"
- "\r\n",
- policy=default,
- )
- self.assertEqual(msg.items(), [
- ("Next-Line", "not\x85broken"),
- ("Null", "not\x00broken"),
- ("Vertical-Tab", "not\vbroken"),
- ("Form-Feed", "not\fbroken"),
- ("File-Separator", "not\x1Cbroken"),
- ("Group-Separator", "not\x1Dbroken"),
- ("Record-Separator", "not\x1Ebroken"),
- ("Line-Separator", "not\u2028broken"),
- ("Paragraph-Separator", "not\u2029broken"),
- ])
- self.assertEqual(msg.get_payload(), "")
+ for parser in self.parsers:
+ with self.subTest(parser=parser.__name__):
+ msg = parser(
+ "Next-Line: not\x85broken\r\n"
+ "Null: not\x00broken\r\n"
+ "Vertical-Tab: not\vbroken\r\n"
+ "Form-Feed: not\fbroken\r\n"
+ "File-Separator: not\x1Cbroken\r\n"
+ "Group-Separator: not\x1Dbroken\r\n"
+ "Record-Separator: not\x1Ebroken\r\n"
+ "Line-Separator: not\u2028broken\r\n"
+ "Paragraph-Separator: not\u2029broken\r\n"
+ "\r\n",
+ policy=default,
+ )
+ self.assertEqual(msg.items(), [
+ ("Next-Line", "not\x85broken"),
+ ("Null", "not\x00broken"),
+ ("Vertical-Tab", "not\vbroken"),
+ ("Form-Feed", "not\fbroken"),
+ ("File-Separator", "not\x1Cbroken"),
+ ("Group-Separator", "not\x1Dbroken"),
+ ("Record-Separator", "not\x1Ebroken"),
+ ("Line-Separator", "not\u2028broken"),
+ ("Paragraph-Separator", "not\u2029broken"),
+ ])
+ self.assertEqual(msg.get_payload(), "")
+
+ class MyMessage(EmailMessage):
+ pass
+
+ def test_custom_message_factory_on_policy(self):
+ for parser in self.parsers:
+ with self.subTest(parser=parser.__name__):
+ MyPolicy = default.clone(message_factory=self.MyMessage)
+ msg = parser("To: foo\n\ntest", policy=MyPolicy)
+ self.assertIsInstance(msg, self.MyMessage)
+
+ def test_factory_arg_overrides_policy(self):
+ for parser in self.parsers:
+ with self.subTest(parser=parser.__name__):
+ MyPolicy = default.clone(message_factory=self.MyMessage)
+ msg = parser("To: foo\n\ntest", Message, policy=MyPolicy)
+ self.assertNotIsInstance(msg, self.MyMessage)
+ self.assertIsInstance(msg, Message)
+
+# Play some games to get nice output in subTest. This code could be clearer
+# if staticmethod supported __name__.
+
+def message_from_file(s, *args, **kw):
+ f = io.StringIO(s)
+ return email.message_from_file(f, *args, **kw)
class TestParser(TestParserBase, TestEmailBase):
- parser = staticmethod(email.message_from_string)
+ parsers = (email.message_from_string, message_from_file)
+
+def message_from_bytes(s, *args, **kw):
+ return email.message_from_bytes(s.encode(), *args, **kw)
+
+def message_from_binary_file(s, *args, **kw):
+ f = io.BytesIO(s.encode())
+ return email.message_from_binary_file(f, *args, **kw)
class TestBytesParser(TestParserBase, TestEmailBase):
- def parser(self, s, *args, **kw):
- return email.message_from_bytes(s.encode(), *args, **kw)
+ parsers = (message_from_bytes, message_from_binary_file)
if __name__ == '__main__':
diff --git a/Lib/test/test_email/test_policy.py b/Lib/test/test_email/test_policy.py
--- a/Lib/test/test_email/test_policy.py
+++ b/Lib/test/test_email/test_policy.py
@@ -5,6 +5,7 @@
import email.policy
import email.parser
import email.generator
+import email.message
from email import headerregistry
def make_defaults(base_defaults, differences):
@@ -23,6 +24,7 @@
'cte_type': '8bit',
'raise_on_defect': False,
'mangle_from_': True,
+ 'message_factory': email.message.Message,
}
# These default values are the ones set on email.policy.default.
# If any of these defaults change, the docs must be updated.
@@ -34,6 +36,7 @@
'refold_source': 'long',
'content_manager': email.policy.EmailPolicy.content_manager,
'mangle_from_': False,
+ 'message_factory': email.message.EmailMessage,
})
# For each policy under test, we give here what we expect the defaults to
@@ -62,20 +65,22 @@
def test_defaults(self):
for policy, expected in self.policies.items():
for attr, value in expected.items():
- self.assertEqual(getattr(policy, attr), value,
- ("change {} docs/docstrings if defaults have "
- "changed").format(policy))
+ with self.subTest(policy=policy, attr=attr):
+ self.assertEqual(getattr(policy, attr), value,
+ ("change {} docs/docstrings if defaults have "
+ "changed").format(policy))
def test_all_attributes_covered(self):
for policy, expected in self.policies.items():
for attr in dir(policy):
- if (attr.startswith('_') or
- isinstance(getattr(email.policy.EmailPolicy, attr),
- types.FunctionType)):
- continue
- else:
- self.assertIn(attr, expected,
- "{} is not fully tested".format(attr))
+ with self.subTest(policy=policy, attr=attr):
+ if (attr.startswith('_') or
+ isinstance(getattr(email.policy.EmailPolicy, attr),
+ types.FunctionType)):
+ continue
+ else:
+ self.assertIn(attr, expected,
+ "{} is not fully tested".format(attr))
def test_abc(self):
with self.assertRaises(TypeError) as cm:
@@ -237,6 +242,9 @@
# wins), but that the order still works (right overrides left).
+class TestException(Exception):
+ pass
+
class TestPolicyPropagation(unittest.TestCase):
# The abstract methods are used by the parser but not by the wrapper
@@ -244,40 +252,40 @@
# policy was actually propagated all the way to feedparser.
class MyPolicy(email.policy.Policy):
def badmethod(self, *args, **kw):
- raise Exception("test")
+ raise TestException("test")
fold = fold_binary = header_fetch_parser = badmethod
header_source_parse = header_store_parse = badmethod
def test_message_from_string(self):
- with self.assertRaisesRegex(Exception, "^test$"):
+ with self.assertRaisesRegex(TestException, "^test$"):
email.message_from_string("Subject: test\n\n",
policy=self.MyPolicy)
def test_message_from_bytes(self):
- with self.assertRaisesRegex(Exception, "^test$"):
+ with self.assertRaisesRegex(TestException, "^test$"):
email.message_from_bytes(b"Subject: test\n\n",
policy=self.MyPolicy)
def test_message_from_file(self):
f = io.StringIO('Subject: test\n\n')
- with self.assertRaisesRegex(Exception, "^test$"):
+ with self.assertRaisesRegex(TestException, "^test$"):
email.message_from_file(f, policy=self.MyPolicy)
def test_message_from_binary_file(self):
f = io.BytesIO(b'Subject: test\n\n')
- with self.assertRaisesRegex(Exception, "^test$"):
+ with self.assertRaisesRegex(TestException, "^test$"):
email.message_from_binary_file(f, policy=self.MyPolicy)
# These are redundant, but we need them for black-box completeness.
def test_parser(self):
p = email.parser.Parser(policy=self.MyPolicy)
- with self.assertRaisesRegex(Exception, "^test$"):
+ with self.assertRaisesRegex(TestException, "^test$"):
p.parsestr('Subject: test\n\n')
def test_bytes_parser(self):
p = email.parser.BytesParser(policy=self.MyPolicy)
- with self.assertRaisesRegex(Exception, "^test$"):
+ with self.assertRaisesRegex(TestException, "^test$"):
p.parsebytes(b'Subject: test\n\n')
# Now that we've established that all the parse methods get the
--
Repository URL: https://hg.python.org/cpython
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