simultaneous assignment

[Grant Edwards]

On 2006-05-02, Boris Borcic <bborcic at gmail.com> wrote:
> Grant Edwards wrote:
>> On 2006-05-02, Boris Borcic <bborcic at gmail.com> wrote:
>>> Grant Edwards wrote:
>>>> Python knows how to count.  :)
>>>>
>>>> def countFalse(seq):
>>>>     return len([v for v in seq if not v])
>>>>
>>>> def countTrue(seq):
>>>>     return len([v for v in seq if v])
>>>>
>>>> def truth_test(seq):
>>>>     return countTrue(seq) == 1
>>>>
>>> I'd suggest the more direct
>>>
>>> def countFalse(seq) :
>>>      return sum(1 for v in seq if not v)
>> 
>> I guess I don't see how that is more direct.
>> 
>> If you want to know how many items are in a seqneuce, you call
>> len().  
>
> sum doesn't construct a sequence

Doh!  I missed the fact that you used a generator rather than a
list comprehension.

>> Converting that list to a list of 1's
>
> that's not what my suggestion is doing

I see that now.

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