[BangPypers] Python List Comprehension Question

[kracekumar ramaraju]

On Thu, Oct 2, 2014 at 6:34 PM, Abhishek L <abhishekl.2006 at gmail.com> wrote:

> On Thu, Oct 2, 2014 at 5:15 PM, kracekumar ramaraju
> <kracethekingmaker at gmail.com> wrote:
> > Hi
> >
> > `yield from ` is introduced in Python 3.3 as part of pep 380.
> >
> > # python 3.3
> >
> > from collections import Iterable
> >
> > def flatten(items):
> >     for item in items:
> >         if isinstance(item, Iterable):
> >             yield from flatten(item)
> >         else:
> >             yield item
>
> Yield from approach is great if you're using python 3.3+ :)
>
> >
> > list(flatten([[1, 2, [3]], 4]))
> > [1, 2, 3, 4]
> >
> > # python 2.7
> >
> > from collections import Iterable
> >
> > x = [[1, 2, [3]], 4]
> >
> > def flatten(items):
> >     for item in items:
> >         if isinstance(item, Iterable):
> >             for subitem in flatten(item):
> >                 yield subitem
> >         else:
> >             yield item
> >    ....:
> >
> > list(flatten(x))
> > [1, 2, 3, 4]
>
> Also you may need to check whether the item is not a string or bytes
> or a string in the list will break this, an
>
> isinstance(item, Iterable) and not isinstance(item,str) # maybe bytes too
>
>
ah, Yes that is correct. Probably flatten can take ignore_types as an
argument.

condition can be
isinstance(item, Iterable) and not isinstance(item, ignore_types)


should handle that
>
> --
> Abhishek
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-- 

*Thanks & Regardskracekumar"Talk is cheap, show me the code" -- Linus
Torvaldshttp://kracekumar.com <http://kracekumar.com>*