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Sat Mar 27 12:12:02 CET 2010 · https://mail.python.org/pipermail/python-dev/2010-March/098946.html

On Thu, Mar 25, 2010 at 1:15 AM, Jeffrey Yasskin <jyasskin at gmail.com> wrote:
> On Wed, Mar 24, 2010 at 2:09 PM, Mark Dickinson <dickinsm at gmail.com> wrote:
>> Slight change of topic.  I've been implementing the extra comparisons
>> required for the Decimal type and found an anomaly while testing.
>> Currently in py3k, order comparisons (but not ==, !=) between a
>> complex number and another complex, float or int raise TypeError:
>>
>>>>> z = complex(0, 0)
>>>>> z < int()
>> Traceback (most recent call last):
>>  File "<stdin>", line 1, in <module>
>> TypeError: unorderable types: complex() < int()
>>>>> z < float()
>> Traceback (most recent call last):
>>  File "<stdin>", line 1, in <module>
>> TypeError: unorderable types: complex() < float()
>>>>> z < complex()
>> Traceback (most recent call last):
>>  File "<stdin>", line 1, in <module>
>> TypeError: unorderable types: complex() < complex()
>>
>> But Fraction is the odd man out:  a comparison between a Fraction and
>> a complex raises a TypeError for complex numbers with nonzero
>> imaginary component, but returns a boolean value if the complex number
>> has zero imaginary component:
>>
>>>>> z < Fraction()
>> False
>>>>> complex(0, 1) < Fraction()
>> Traceback (most recent call last):
>>  File "<stdin>", line 1, in <module>
>> TypeError: unorderable types: complex() < Fraction()
>>
>> I'm tempted to call this Fraction behaviour a bug, but maybe it arises
>> from the numeric integration themes of PEP 3141.  Any ideas?
>
> I'd call it a bug.
>

Thanks, Jeffrey (and everyone else who answered).  Fixed in r79456
(py3k) and r79455 (trunk).

Mark

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[Python-Dev] Mixing float and Decimal -- thread reboot