[Python-3000] Is this a bug ?

[Anand Balachandran Pillai]

Hi,

On Tue, Apr 8, 2008 at 6:50 PM, Amaury Forgeot d'Arc <amauryfa at gmail.com> wrote:
> Hello,
>
>
>
>  Anand Balachandran Pillai wrote:
>  > While playing around with true & floor division in Py3k...
>  >
>  >  Python 3.0a4+ (py3k:62126, Apr  3 2008, 16:28:40)
>  >  [GCC 4.1.2 20070626 (Red Hat 4.1.2-13)] on linux2
>  >  Type "help", "copyright", "credits" or "license" for more information.
>  >  >>> x=2+0j
>  >  >>> y=3+0j
>  >  >>> x / y
>  >  (0.66666666666666663+0j)
>  >  >>> x//y
>  >  Traceback (most recent call last):
>  >   File "<stdin>", line 1, in <module>
>  >  TypeError: can't take floor of complex number.
>  >  >>> x.__floordiv__(y)
>  >  Traceback (most recent call last):
>  >   File "<stdin>", line 1, in <module>
>  >  TypeError: can't take floor of complex number.
>  >  >>> x.__divmod__(y)
>  >  Traceback (most recent call last):
>  >   File "<stdin>", line 1, in <module>
>  >  TypeError: can't take floor or mod of complex number.
>  >
>  >  In Python2.5,
>  >
>  >  [anand at localhost py3k]$ python2.5
>  >  Python 2.5.1 (r251:54863, Sep  6 2007, 17:27:08)
>  >  [GCC 4.1.1 20061011 (Red Hat 4.1.1-30)] on linux2
>  >  Type "help", "copyright", "credits" or "license" for more information.
>  >  >>> x=2+0j
>  >  >>> y=3+0j
>  >  >>> x/y
>  >  (0.66666666666666663+0j)
>  >  >>> x//y
>  >  __main__:1: DeprecationWarning: complex divmod(), // and % are deprecated
>  >  0j
>  >  >>> x.__floordiv__(y)
>  >  0j
>  >  >>> x.__divmod__(y)
>  >  (0j, (2+0j))
>  >
>  >  Shouldn't Py3k also return 0j for floor division ? If it does not want to do
>  >  floor division/divmod for complex numbers, shouldn't the exception
>  >  error be more descriptive ? Or is this the expected behavior ?
>
>  Yes, the DeprecationWarning has turned into a real error.
>  This is the normal evolution of python 3.0.

Thanks for the clarification.

>
>  Then, I find the message quite descriptive:
>     >>> divmod(x,y)
>
>     TypeError: can't take floor or mod of complex number.
>  What message would you want in this case?

The message "can't take floor..." is slightly confusing since it could
mean the floor or mod cannot be taken in this context, instead of
conveying the (correct) information that this operation is invalid
in any context.

A message like "can't convert complex to float" or "Invalid operation,
can't perform floor or mod on complex number", would be more
informative.

>
>  --
>  Amaury Forgeot d'Arc
>


Thanks

-- 
-Anand