easy question on parsing python: "is not None"

[Chris Rebert]

On Thu, Aug 5, 2010 at 8:56 AM, Roald de Vries <downaold at gmail.com> wrote:
> On Aug 5, 2010, at 5:42 PM, wheres pythonmonks wrote:
>> How does "x is not None" make any sense?  "not x is None" does make sense.
>>
>> I can only surmise that in this context (preceding is) "not" is not a
>> unary right-associative operator, therefore:
>>
>> x is not None === IS_NOTEQ(X, None)
>>
>> Beside "not in" which seems to work similarly, is there other
>> syntactical sugar like this that I should be aware of?
>
> 'not None' first casts None to a bool, and then applies 'not', so 'x is not
> None' means 'x is True'.

Absolutely incorrect. Read the final paragraph of
http://docs.python.org/reference/expressions.html#notin

Cheers,
Chris
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