[BangPypers] Truth Tests (bool)
saager.mhatre at gmail.com
Fri Jan 13 14:24:27 CET 2012
On Wed, Jan 11, 2012 at 9:49 AM, Noufal Ibrahim <noufal at nibrahim.net.in>wrote:
> Gora Mohanty <gora at mimirtech.com> writes:
> > It is not clear what you want from your description. To check if a
> > list is empty, see if len( list ) is zero.
> You don't want to do that. Your "list" might be a generator (unless you
> check for type which is a bad idea anyway) and "len"ing that will
> consume it which might be a potentially expensive operation.
Noticed something interesting as I was updating
include generators and generator expressions; the `len` function doesn't
handle generators at all.
$ *python -c 'len(i for i in range(10))'*
Traceback (most recent call last):
File "<string>", line 1, in <module>
TypeError: object of type 'generator' has no len()
I'm pretty sure you just meant 'iterable' where you wrote 'generator', or
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