[issue10017] pprint.pprint raises TypeError on dictionaries with user-defined types as keys
Roundup Robot devn...@psf.upfronthosting.co.za added the comment: New changeset 03cda5360dc6 by Florent Xicluna in branch '3.2': Issues #10017 and #14998: Fix TypeError using pprint on dictionaries with unorderable key. http://hg.python.org/cpython/rev/03cda5360dc6 New changeset 4d0dcfbdf45b by Florent Xicluna in branch 'default': Issues #10017 and #14998: Fix TypeError using pprint on dictionaries with unorderable key. http://hg.python.org/cpython/rev/4d0dcfbdf45b -- nosy: +python-dev ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue10017 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue10017] pprint.pprint raises TypeError on dictionaries with user-defined types as keys
Florent Xicluna florent.xicl...@gmail.com added the comment: Thanks for this patch. I've reviewed the issue and merged the patch of issue #14998 which fixes both cases. -- resolution: - fixed stage: needs patch - committed/rejected status: open - closed superseder: - pprint._safe_key is not always safe enough ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue10017 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue10017] pprint.pprint raises TypeError on dictionaries with user-defined types as keys
Florent Xicluna florent.xicl...@gmail.com added the comment: Confirmed on python 3.2 and 3.3. -- keywords: +easy nosy: +flox stage: - needs patch type: - behavior versions: +Python 3.2, Python 3.3 -Python 3.1 ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue10017 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue10017] pprint.pprint raises TypeError on dictionaries with user-defined types as keys
Changes by Anton Barkovsky swarmer...@gmail.com: -- nosy: +anton.barkovsky ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue10017 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue10017] pprint.pprint raises TypeError on dictionaries with user-defined types as keys
Anton Barkovsky swarmer...@gmail.com added the comment: Here's a patch with fix and tests. Note that class objects are not comparable and have the same type so they fall back on sorting by id. Should we sort them by name as a special case instead? -- keywords: +patch Added file: http://bugs.python.org/file26433/pprint_fix.patch ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue10017 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue10017] pprint.pprint raises TypeError on dictionaries with user-defined types as keys
Changes by Giampaolo Rodola' g.rod...@gmail.com: -- nosy: +giampaolo.rodola ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue10017 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue10017] pprint.pprint raises TypeError on dictionaries with user-defined types as keys
Rodrigo Bernardo Pimentel r...@isnomore.net added the comment: FWIW, the problem still occurs on the most recent release31-maint checkout (as of r85323), and does not happen on py3k (3.2a2). -- nosy: +rbp ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue10017 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue10017] pprint.pprint raises TypeError on dictionaries with user-defined types as keys
Rodrigo Bernardo Pimentel r...@isnomore.net added the comment:
If I'm understanding this correctly, this fails on 3.1 and not (although,
actually, it does) on py3k/3.2 because:
* pprint._safe_key.__lt__ checks rv = self.obj.__lt__(other.obj) and falls
back to id comparison if rv is NotImplemented
* If the object passed to _safe_key is a class, self.obj.__lt__ will expect
*self* as well as the other object. Therefore the verification above fails with
TypeError: expected 1 arguments, got 0. You can see that pprint works with an
instance:
pprint.pprint({A(): 1, 1: 2})
{__main__.A object at 0x8594d4c: 1, 1: 2}
* Finally, this works on py3k *for your example* because, for some reason, on
py3k the comparison is being based on the 1 key. That is, the comparison on
_safe_key.__lt__ happens to be 1.__lt__(A), instead of A.__lt__(1). Perhaps
hashing changed after the 3.1 release?
Anyway, py3k still fails when you force the comparison to happen on the class:
class B(object): pass
...
pprint.pprint({A: 1, B: 2})
Traceback (most recent call last):
File stdin, line 1, in module
File /home/rbp/python/dev/py3k/Lib/pprint.py, line 55, in pprint
printer.pprint(object)
File /home/rbp/python/dev/py3k/Lib/pprint.py, line 132, in pprint
self._format(object, self._stream, 0, 0, {}, 0)
File /home/rbp/python/dev/py3k/Lib/pprint.py, line 155, in _format
rep = self._repr(object, context, level - 1)
File /home/rbp/python/dev/py3k/Lib/pprint.py, line 245, in _repr
self._depth, level)
File /home/rbp/python/dev/py3k/Lib/pprint.py, line 257, in format
return _safe_repr(object, context, maxlevels, level)
File /home/rbp/python/dev/py3k/Lib/pprint.py, line 299, in _safe_repr
items = sorted(object.items(), key=_safe_tuple)
File /home/rbp/python/dev/py3k/Lib/pprint.py, line 89, in __lt__
rv = self.obj.__lt__(other.obj)
TypeError: expected 1 arguments, got 0
So, basically, the fix on issue 3976 does't (always) work when there are
classes as dict keys. I think switching from
rv = self.obj.__lt__(other.obj)
if rv is NotImplemented:
to something like
try:
rv = self.obj other.obj
except TypeError:
rv = (str(type(self.obj)), id(self.obj)) \
(str(type(other.obj)), id(other.obj))
solves this. Or we can check first whether self.obj is a 'type', but I think it
gets convoluted.
If anyone can confirm that that's the way to go, I can produce one (though it's
a trivial one). Raymond?
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[issue10017] pprint.pprint raises TypeError on dictionaries with user-defined types as keys
Amaury Forgeot d'Arc amaur...@gmail.com added the comment: A simpler change would to replace: rv = self.obj.__lt__(other.obj) with rv = type(self.obj).__lt__(self.obj, other.obj) -- nosy: +amaury.forgeotdarc ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue10017 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue10017] pprint.pprint raises TypeError on dictionaries with user-defined types as keys
New submission from Arnaud Delobelle arno...@googlemail.com:
The pprint function in the python 3.1 pprint module fails when
printing a dictionary containing more than one item and with one item
being a user-defined type. It seems pprint tries to sort the keys but
fails, (maybe because calling __lt__ on a user-defined type doesn't
bind its first argument to 'self'? Looking into pprint.py would
probably yield the answer).
This seems related to issue 3976 but it was fixed in r76389 and
r76390. My example below fails in r79147. I'm not in a position to check more
recent revisions right now.
In Python 2.6, the following works fine:
Python 2.6.5 (r265:79063, Apr 16 2010, 13:09:56)
[GCC 4.4.3] on linux2
Type help, copyright, credits or license for more information.
from pprint import pprint
class A(object): pass
...
pprint({A:1, 1:2})
{1: 2, class __main__.A at 0xb77dc47c: 1}
But in Python 3.1, it fails with the error below:
Python 3.1.2 (r312:79147, Apr 15 2010, 12:35:07)
[GCC 4.4.3] on linux2
Type help, copyright, credits or license for more information.
from pprint import pprint
class A: pass
...
pprint({A:1, 1:2})
Traceback (most recent call last):
File stdin, line 1, in module
File /usr/lib/python3.1/pprint.py, line 55, in pprint
printer.pprint(object)
File /usr/lib/python3.1/pprint.py, line 132, in pprint
self._format(object, self._stream, 0, 0, {}, 0)
File /usr/lib/python3.1/pprint.py, line 155, in _format
rep = self._repr(object, context, level - 1)
File /usr/lib/python3.1/pprint.py, line 242, in _repr
self._depth, level)
File /usr/lib/python3.1/pprint.py, line 254, in format
return _safe_repr(object, context, maxlevels, level)
File /usr/lib/python3.1/pprint.py, line 296, in _safe_repr
items = sorted(object.items(), key=_safe_tuple)
File /usr/lib/python3.1/pprint.py, line 89, in __lt__
rv = self.obj.__lt__(other.obj)
TypeError: expected 1 arguments, got 0
--
components: Library (Lib)
messages: 117895
nosy: arno
priority: normal
severity: normal
status: open
title: pprint.pprint raises TypeError on dictionaries with user-defined types
as keys
versions: Python 3.1
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[issue10017] pprint.pprint raises TypeError on dictionaries with user-defined types as keys
Changes by R. David Murray rdmur...@bitdance.com: -- nosy: +rhettinger ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue10017 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
