[Zope] Boolean properties ( Zope 2.5)

Eron Lloyd elloyd@lancaster.lib.pa.us
04 Sep 2002 18:54:53 -0400


Correct, but that's only when doing a comparison. Python will perform a
lazy comparison, returning either the first true value (in an "or"
expr.), or the last true value in an "and" expr. In the case stated,
it's not so much a question of logic as it is value representation.
Honestly, I don't understand why you would ever want the actual *value*
returned by a boolean expression, instead of it's state. What needs to
be done probably is a re-examination of the problem at hand.

Cheers,

Eron

On Wed, 2002-09-04 at 18:29, Chris Beaven wrote:
> In Python, 'and' and 'or' perform boolean logic as you would expect, but
> they do not return boolean values; they return one of the actual values they
> are comparing. 
> 
> >>> 'a' and 'b'
> 'b'
> >>> '' and 'b'
> ''
> 
> >>> 'a' or 'b'
> 'a'
> >>> '' or 'b'
> 'b'
> 
> http://diveintopython.org/apihelper_andor.html
> 
> Well, I found it interesting...
> 
> 
> -----Original Message-----
> From: Brian Sullivan [mailto:brians@meetingbywire.com]
> Sent: Thursday, 5 September 2002 2:27 a.m.
> To: zope@zope.org
> Subject: [Zope] Boolean properties ( Zope 2.5)
> 
> 
> I a trying to figure out what values are stored in Boolean typed
> properties of a Zope object in order to display information in and
> retrieve and set information from form checkboxes.
> 
> What values are actually set/returned in boolean properties?
> 
> 
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