New submission from Shawn Brown <03sjbr...@gmail.com>:
This is related to resolved issue 3976 and, to a lesser extent, issue 10017.
I've run across another instance where pprint throws an exception (but works
fine in 2.7 and earlier):
Python 3.2 (r32:88445, Mar 25 2011, 19:28:28)
[GCC 4.5.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> from pprint import pprint
>>> pprint({(0,): 1, (None,): 2})
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/usr/lib/python3.2/pprint.py", line 55, in pprint
printer.pprint(object)
File "/usr/lib/python3.2/pprint.py", line 132, in pprint
self._format(object, self._stream, 0, 0, {}, 0)
File "/usr/lib/python3.2/pprint.py", line 155, in _format
rep = self._repr(object, context, level - 1)
File "/usr/lib/python3.2/pprint.py", line 245, in _repr
self._depth, level)
File "/usr/lib/python3.2/pprint.py", line 257, in format
return _safe_repr(object, context, maxlevels, level)
File "/usr/lib/python3.2/pprint.py", line 299, in _safe_repr
items = sorted(object.items(), key=_safe_tuple)
File "/usr/lib/python3.2/pprint.py", line 89, in __lt__
rv = self.obj.__lt__(other.obj)
TypeError: unorderable types: int() < NoneType()
The above example might seem contrived but I stumbled across the issue quite
naturally. Honest!
In working with multiple lists and computing results using combinations of
these lists' values. I _could_ organize the results as a dictionary of
dictionaries of dictionaries but that would get confusing very quickly.
Instead, I'm using a single dictionary with a composite key ("flat is better
than nested"). So I've got code like this...
>>> combinations = itertools.product(lst_x, lst_y, lst_z)
>>> results = {(x,y,z): compute(x,y,z) for x,y,z in combinations}
... and it is not uncommon for one or more of the values to be None --
resulting in the above exception should anyone (including unittest) attempt to
pprint the dictionary.
----------
components: Library (Lib)
messages: 162249
nosy: Shawn.Brown
priority: normal
severity: normal
status: open
title: pprint._safe_key is not always safe enough
versions: Python 3.2
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Python tracker <rep...@bugs.python.org>
<http://bugs.python.org/issue14998>
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