new-style exceptions

[mwhudson]

BPO	1104669
Nosy	@mwhudson, @tim-one, @brettcannon, @ncoghlan, @simonpercivall
Files	new-new-new-new-new-style-exceptions.diff: mwh's attempt Update Python Software Foundation Copyright Year. #4

^{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 = None
closed_at = <Date 2006-03-01.04:35:57.000>
created_at = <Date 2005-01-18.18:09:36.000>
labels = ['interpreter-core']
title = 'new-style exceptions'
updated_at = <Date 2006-03-01.04:35:57.000>
user = 'https://github.com/mwhudson'

bugs.python.org fields:

activity = <Date 2006-03-01.04:35:57.000>
actor = 'brett.cannon'
assignee = 'none'
closed = True
closed_date = None
closer = None
components = ['Interpreter Core']
creation = <Date 2005-01-18.18:09:36.000>
creator = 'mwh'
dependencies = []
files = ['6445']
hgrepos = []
issue_num = 1104669
keywords = ['patch']
message_count = 15.0
messages = ['47572', '47573', '47574', '47575', '47576', '47577', '47578', '47579', '47580', '47581', '47582', '47583', '47584', '47585', '47586']
nosy_count = 7.0
nosy_names = ['mwh', 'tim.peters', 'brett.cannon', 'mcherm', 'jimjjewett', 'ncoghlan', 'simon.percivall']
pr_nums = []
priority = 'normal'
resolution = 'accepted'
stage = None
status = 'closed'
superseder = None
type = None
url = 'https://bugs.python.org/issue1104669'
versions = ['Python 2.5']

[mwhudson]

This patch allows new-style exceptions and makes Exception a
new-style class.

The test suite runs, apart from failures in test_tempfile (will dig,
but doubt this is my fault) and test__locale (known OS X problem).

[simonpercivall]

Logged In: YES
user_id=329382

One thing: Raising an old-style class/instance doesn't give a traceback or
populate sys.last_*.

[mwhudson]

Logged In: YES
user_id=6656

You're right! Odd. No time to fix it today, I'm afraid.

[mwhudson]

Logged In: YES
user_id=6656

New patch attached. Did this a while ago, don't actually remember the
details of what's new :-/

The problem with the previous patch was that one of my exception-
checking macros had the side-effect of clearing any pending exception...

[mwhudson]

Logged In: YES
user_id=6656

I found the final wart (caught by test_tempfile of all things). I think the
attached is good to go.

Issues remaining: test_pickletools fails, because PickleError is now new-
style and thus pickles differently. Docs.

[tim-one]

Logged In: YES
user_id=31435

FYI, there's nothing special about PicklingError in the
pickletools doctest, it's just aiming at an example of an
instance -- that it's also an exception instance is irrelevant
to what the test is aiming at.

Tell you what: I'll check in a suitable change to
pickletools.py, so that the example it uses stops interfering
with this patch.

[tim-one]

Logged In: YES
user_id=31435

FYI, there's nothing special about PicklingError in the
pickletools doctest, it's just aiming at an example of an
instance -- that it's also an exception instance is irrelevant
to what the test is aiming at.

Tell you what: I'll check in a suitable change to
pickletools.py, so that the example it uses stops interfering
with this patch.

[jimjjewett]

Logged In: YES
user_id=764593

Several lines near the end of errors.c had no visible
change. Was this a whitespace cleanup, or is this a risk of
tab/space mixing?

[mwhudson]

Logged In: YES
user_id=6656

Jim: Yes. It looks like I ran delete-trailing-whitespace on the file at
some point. I could redo the diff without them, but it would be tedious...

Tim: thanks!

[jimjjewett]

Logged In: YES
user_id=764593

Is it worth adding a comment on parsing precedence?

An object can be both an instance and a class, which puts
some ambiguity between "raise class" and "raise
classinstance".

Assuming the class seems sensible; I'm just wondering
whether it should be made explicit. (Making something
both an instance and a subclass of anything besides object
might be weird enough that you don't *want* to document
the results yet.)

[mwhudson]

Logged In: YES
user_id=6656

Is it worth adding a comment on parsing precedence?

I've been studiously avoiding thinking about that :)

Making something both an instance and a subclass of
anything besides object might be weird enough that you
don't *want* to document the results yet.

Quite. What happens, happens IMHO. I'm prepared to be argued into a
different position on this, but I do think the only reason someone would
do this is curiousity :)