[Python-ideas] Programming recommendations (PEP 8) and boolean values

Rob Cliffe rob.cliffe at btinternet.com
Thu Aug 9 10:09:35 CEST 2012

On 09/08/2012 06:48, Georg Brandl wrote:
> On 08.08.2012 23:56, Ned Batchelder wrote:
>> On 8/8/2012 4:29 PM, Georg Brandl wrote:
>>> For None, "==" and "is" are equivalent, because no other object is 
>>> equal
>>> to None.  For True and False, this is different, and using "is" here is
>>> a very stealthy bug.
>> It's easy to make other objects == None, by writing buggy __eq__
>> methods.  That doesn't happen much, but it's easier with __ne__, where
>> the negated logic is easy to screw up.  I've seen it happen. Use "is
>> None", not "== None".
> That's true indeed.
> Georg
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Surely that's a reason to fix the buggy __eq__ and __ne__ methods, not 
to avoid using them.
(Sorry Georg I accidentally replied to you not to the list.)
Rob Cliffe

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