On 2009-02-10, Albert Hopkins wrote:
> On Tue, 2009-02-10 at 12:50 -0800, Josh Dukes wrote:
>
> I don't understand what you mean by this. But if you really want to
> know if a generator is "non-empty":
>
> def non_empty(virgin_generator):
> try:
> virgin_generator.next() # note you ju
On Tue, 2009-02-10 at 12:50 -0800, Josh Dukes wrote:
The thing I don't understand is why a generator that has no iterable
values is different from an empty list. Why shouldn't bool ==
has_value?? Technically a list, a tuple, and a string are also objects
but if they lack values they're evaluated
Josh Dukes wrote:
I was actually aware of that (thank you, though, for trying to help).
What I was not clear on was if the boolean evaluation is a method of an
object that can be modified via operatior overloading (in the same way
+ is actually .__add__()) or not. Clearly __nonzero__ is the ope
ahhh any! ok, yeah, I guess that's what I was looking for. Thanks.
On 10 Feb 2009 21:57:56 GMT
Steven D'Aprano wrote:
> On Tue, 10 Feb 2009 12:50:02 -0800, Josh Dukes wrote:
>
> > The thing I don't understand is why a generator that has no iterable
> > values is different from an empty list.
>
On Tue, Feb 10, 2009 at 1:57 PM, Steven D'Aprano
wrote:
> On Tue, 10 Feb 2009 12:50:02 -0800, Josh Dukes wrote:
>
>> The thing I don't understand is why a generator that has no iterable
>> values is different from an empty list.
>
> How do you know it has no iterable values until you call next() o
On Tue, 10 Feb 2009 12:50:02 -0800, Josh Dukes wrote:
> The thing I don't understand is why a generator that has no iterable
> values is different from an empty list.
How do you know it has no iterable values until you call next() on it and
get StopIteration?
By the way, your "has_values" funct
On Tue, 2009-02-10 at 12:50 -0800, Josh Dukes wrote:
> The thing I don't understand is why a generator that has no iterable
> values is different from an empty list. Why shouldn't bool ==
> has_value?? Technically a list, a tuple, and a string are also objects
> but if they lack values they're eva
> The first example is a list. A list of length 0 evaluates to False.
>
> The second example returns a generator object. A generator object
> apparently evaluates to true. Your example is not iterating of their
> values of the generator, but evaluating bool(generator_object) itself.
> My feelin
On Tue, 2009-02-10 at 11:15 -0800, Josh Dukes wrote:
> quite simply...what???
>
> In [108]: bool([ x for x in range(10) if False ])
> Out[108]: False
>
> In [109]: bool( x for x in range(10) if False )
> Out[109]: True
>
> Why do these two evaluate differently? I was expecting that they would
>
On Tue, Feb 10, 2009 at 11:15 AM, Josh Dukes wrote:
> quite simply...what???
>
> In [108]: bool([ x for x in range(10) if False ])
> Out[108]: False
This evaluates the list comprehension and creates an empty list, which
is considered boolean False by Python.
> In [109]: bool( x for x in range(10
quite simply...what???
In [108]: bool([ x for x in range(10) if False ])
Out[108]: False
In [109]: bool( x for x in range(10) if False )
Out[109]: True
Why do these two evaluate differently? I was expecting that they would
evaluate the same but the generator would return true *as soon as the
fir
11 matches
Mail list logo
