email.Message does not allow iteration

[ptmcg]

BPO	1017329
Nosy	@warsaw

^{Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.}

Show more details

GitHub fields:

assignee = 'https://github.com/warsaw'
closed_at = <Date 2004-11-01.13:40:57.000>
created_at = <Date 2004-08-27.02:11:01.000>
labels = ['extension-modules']
title = 'email.Message does not allow iteration'
updated_at = <Date 2004-11-01.13:40:57.000>
user = 'https://bugs.python.org/ptmcg'

bugs.python.org fields:

activity = <Date 2004-11-01.13:40:57.000>
actor = 'barry'
assignee = 'barry'
closed = True
closed_date = None
closer = None
components = ['Extension Modules']
creation = <Date 2004-08-27.02:11:01.000>
creator = 'ptmcg'
dependencies = []
files = []
hgrepos = []
issue_num = 1017329
keywords = []
message_count = 2.0
messages = ['22232', '22233']
nosy_count = 2.0
nosy_names = ['barry', 'ptmcg']
pr_nums = []
priority = 'normal'
resolution = 'wont fix'
stage = None
status = 'closed'
superseder = None
type = None
url = 'https://bugs.python.org/issue1017329'
versions = []

[ptmcg]

From comp.lang.python:

"Roman Suzi" <rnd@onego.ru> wrote in message
news:mailman.2348.1093434827.5135.python-
list@python.org...
>
> In Python2.3.4:
>
> >>> em = email.message_from_file(open
('MAILMESSAGE'))
> >>> for i in em:
> ...   print i
> ...
> Traceback (most recent call last):
>   File "<stdin>", line 1, in ?
>   File "/usr/lib/python2.3/email/Message.py",
> line
> 304, in __getitem__
>   File "/usr/lib/python2.3/email/Message.py",
> line
> 370, in get
> AttributeError: 'int' object has no attribute 'lower'

In this example, em is an email.Message object. The
Message acts as a pseudo-dictionary, containing a list of
e-mail fields, organized by name and contents.

The problem occurs because __getitem__ assumes that
the provided index is a name into a dictionary. For
programmer convenience, keys in the Message are case-
insensitive, so __getitem__ starts by calling lower() on
the provided name. Apparently, the attempt to iterate
over Message successively calls __getitem__ with
integers from 0 to len(em). Integers don't like having
lower() called, though.

To fix this problem:

• have __getitem__ use the input arg as a name if it is
  of type string; otherwise, just use the provided arg as
  an index to the underlying self.headers list (arg could
  be either an integer or a slice, so don't just test for
  integer!)
• make a similar change to __delitem__ - it too
  assumes that the incoming arg is a string, naming a
  header field to be deleted; must test first to see if arg is
  an integer or slice
• add __iter__ method, which returns iter(self.headers)

-- Paul

[warsaw]

Logged In: YES
user_id=12800

Header iteration is already supported by .keys(), .values(),
and .items() and it's ambiguous whether "for x in msg"
should return the headers or in the case of multiparts, the
subparts.