[issue19146] Improvements to traceback module
Guido van Rossum added the comment: I decided to abandon this project and close the issue as wontfix. -- resolution: - wont fix stage: patch review - committed/rejected status: open - closed ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue19146 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue19146] Improvements to traceback module
Antoine Pitrou added the comment: And adding __slots__ to a namedtuple subclass doesn't work. Are you sure? I do it all the time. -- nosy: +pitrou ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue19146 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue19146] Improvements to traceback module
Guido van Rossum added the comment:
Well this is what I get:
$ python3
Python 3.4.0a1+ (default:41de6f0e62fd+, Aug 27 2013, 18:44:07)
[GCC 4.2.1 Compatible Apple LLVM 4.2 (clang-425.0.28)] on darwin
Type help, copyright, credits or license for more information.
from collections import namedtuple
from collections import namedtuple
A = namedtuple('A', 'foo bar')
A = namedtuple('A', 'foo bar')
class B(A):
class B(A):
... __slots__ = ['baz']
__slots__ = ['baz']
...
Traceback (most recent call last):
File stdin, line 1, in module
TypeError: nonempty __slots__ not supported for subtype of 'A'
When I try to set __slots__ on an existing namedtuple it doesn't complain, but
it doesn't work either:
A.__slots__ = ['xxx']
a.xxx = 1
Traceback (most recent call last):
File stdin, line 1, in module
AttributeError: 'A' object has no attribute 'xxx'
What am I doing wrong?
--
___
Python tracker rep...@bugs.python.org
http://bugs.python.org/issue19146
___
___
Python-bugs-list mailing list
Unsubscribe:
https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue19146] Improvements to traceback module
Antoine Pitrou added the comment:
Well this is what I get:
$ python3
Python 3.4.0a1+ (default:41de6f0e62fd+, Aug 27 2013, 18:44:07)
[GCC 4.2.1 Compatible Apple LLVM 4.2 (clang-425.0.28)] on darwin
Type help, copyright, credits or license for more information.
from collections import namedtuple
from collections import namedtuple
A = namedtuple('A', 'foo bar')
A = namedtuple('A', 'foo bar')
class B(A):
class B(A):
... __slots__ = ['baz']
__slots__ = ['baz']
...
Traceback (most recent call last):
File stdin, line 1, in module
TypeError: nonempty __slots__ not supported for subtype of 'A'
Ah, ok, you're right. I only use empty __slots__ :-)
--
___
Python tracker rep...@bugs.python.org
http://bugs.python.org/issue19146
___
___
Python-bugs-list mailing list
Unsubscribe:
https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue19146] Improvements to traceback module
Changes by Guido van Rossum gu...@python.org: -- stage: - patch review type: - enhancement versions: +Python 3.4, Python 3.5 ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue19146 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue19146] Improvements to traceback module
New submission from Guido van Rossum: The traceback module is driving me nuts. It has some handy helpers to extract info about a traceback or a full stack without formatting them, but (a) these are _internal, and (b) they don't return the frame object as part of the information, so code that wants to do additional stuff (e.g. print the values of local variables) cannot use them. (I guess in a sense the two problems cancel each other out. :-) Here's a proposed fix. (I know it is lacking tests.) It adds extract_tb_ex() and extract_stack_ex() functions that return a list of 5-tuples filename, line number, function name, text, frame). I'm also reworking the lowest-level internal function, _extract_tb_or_stack_iter(), to take an iterator instead of a starting point and a function to get the info and the next starting point. The old design feels unpythonic to me -- the task at hand so clearly feels like it should wrap an iterator! Finally, I'm adding some important info to a few docstrings: when the limit clips the number of frames, you get the *oldest* frames from a traceback, but the *newest* frames from a stack. That makes sense when you think about it, but I still think it's worth mentioning. Feedback? -- messages: 198852 nosy: akuchling, benjamin.peterson, gvanrossum priority: normal severity: normal status: open title: Improvements to traceback module ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue19146 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue19146] Improvements to traceback module
Serhiy Storchaka added the comment: You forgot a patch. -- nosy: +serhiy.storchaka ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue19146 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue19146] Improvements to traceback module
Guido van Rossum added the comment: Sigh. Here it is. -- keywords: +patch Added file: http://bugs.python.org/file31946/TB.patch ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue19146 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue19146] Improvements to traceback module
Changes by Claudiu.Popa pcmantic...@gmail.com: -- nosy: +Claudiu.Popa ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue19146 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue19146] Improvements to traceback module
STINNER Victor added the comment: It adds extract_tb_ex() and extract_stack_ex() functions ... I don't like _ex suffixes, it's not future proof if we need to add another function later. You may rename them using _iter suffix and return an iterator instead of a list. Such idea was also proposed for os.listdir() = os.scandir() / os.iterdir(). See the discussion in #11406. The caller can write tuple(extract_stack_iter()), as I do with dict.items() to sort a dictionary. Feedback? I like unit tests :-) The patch should also document new functions. You may only need the most recent frames. -- nosy: +haypo ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue19146 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue19146] Improvements to traceback module
Guido van Rossum added the comment: I don't like _ex suffixes, it's not future proof if we need to add another function later. Me neither, but you can't change a function that returns a list of 4-tuples into a function that returns a list of 5-tuples without breaking existing code. IIRC for struct and time tuples we created a hack in C where we return something that behaves like an N-tuple but has some extra attributes -- but I don't think collections.namedtuple supports that. You may rename them using _iter suffix and return an iterator instead of a list. I already thought of that, but that doesn't work: the iterator version would return the stack in the wrong order (note the .reverse() call in the code). Such idea was also proposed for os.listdir() = os.scandir() / os.iterdir(). See the discussion in #11406. The caller can write tuple(extract_stack_iter()), as I do with dict.items() to sort a dictionary. I like unit tests :-) The patch should also document new functions. I'll take care of that when we've agreed on the new API. You may only need the most recent frames. Not sure what you mean by that. -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue19146 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue19146] Improvements to traceback module
Claudiu.Popa added the comment: I already thought of that, but that doesn't work: the iterator version would return the stack in the wrong order (note the .reverse() call in the code). Then, couldn't this: stack = list(_extract_stack_iter(_get_stack(f), limit=limit)) stack.reverse() return stack be rewritten as this, knowing the fact that _extract_stack_iter returns an iterable? return reversed(_extract_stack_iter(_get_stack(f), limit=limit)) And in this case, extract_stack_ex could become extract_stack_iter or something like that. -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue19146 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue19146] Improvements to traceback module
Guido van Rossum added the comment: No, reversed() doesn't work on iterators. -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue19146 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue19146] Improvements to traceback module
Serhiy Storchaka added the comment:
Me neither, but you can't change a function that returns a list of 4-tuples
into a function that returns a list of 5-tuples without breaking existing
code. IIRC for struct and time tuples we created a hack in C where we
return something that behaves like an N-tuple but has some extra attributes
-- but I don't think collections.namedtuple supports that.
It do.
class tb_entity(namedtuple('tb_entity', 'filename lineno name line')):
def __new__(cls, filename, lineno, name, line, frame=None):
self = super().__new__(cls, filename, lineno, name, line)
self.frame = frame
return self
--
___
Python tracker rep...@bugs.python.org
http://bugs.python.org/issue19146
___
___
Python-bugs-list mailing list
Unsubscribe:
https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue19146] Improvements to traceback module
Guido van Rossum added the comment: Nice. However it will take up a lot more space, because now there's an instance dict. (And adding __slots__ to a namedtuple subclass doesn't work.) I'll have to think about whether I care about the extra space. -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue19146 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
