Short-circuit Logic

[Terry Jan Reedy]

On 5/26/2013 4:22 PM, Roy Smith wrote:
> In article <mailman.2196.1369599562.3114.python-list at python.org>,
>   Terry Jan Reedy <tjreedy at udel.edu> wrote:
>
>> On 5/26/2013 7:11 AM, Ahmed Abdulshafy wrote:
>>
>>>        if not allow_zero and abs(x) < sys.float_info.epsilon:
>>>                   print("zero is not allowed")
>>
>> The reason for the order is to do the easy calculation first and the
>> harder one only if the first passes.
>
> This is a particularly egregious case of premature optimization.  You're
> worried about how long it takes to execute abs(x)?  That's silly.

This is a particularly egregious case of premature response. You're 
ignoring an extra name lookup and two extra attribute lookups. That's silly.

That's beside the fact that one *must* choose, so any difference is a 
reason to act rather than being frozen like Buridan's ass.
http://en.wikipedia.org/wiki/Buridan%27s_ass

If you wish, replace 'The reason' with 'A reason'. I also the logical 
flow as better with the order given.