Pythonic way of saying 'at least one of a, b, or c is in some_list'

[nn]

On Oct 28, 12:33 pm, "cbr... at cbrownsystems.com"
<cbr... at cbrownsystems.com> wrote:
> On Oct 28, 9:23 am, John Posner <jjpos... at optimum.net> wrote:
>
>
>
> > On 10/28/2010 12:16 PM, cbr... at cbrownsystems.com wrote:
>
> > > It's clear but tedious to write:
>
> > > if 'monday" in days_off or "tuesday" in days_off:
> > >      doSomething
>
> > > I currently am tending to write:
>
> > > if any([d for d in ['monday', 'tuesday'] if d in days_off]):
> > >      doSomething
>
> > > Is there a better pythonic idiom for this situation?
>
> > Clunky, but it might prompt you to think of a better idea: convert the
> > lists to sets, and take their intersection.
>
> > -John
>
> I thought of that as well, e.g.:
>
> if set(["monday,"tuesday']).intersection(set(days_off)):
>     doSomething
>
> but those extra recasts to set() make it unaesthetic to me; and worse
>
> if not set(["monday,"tuesday']).isdisjoint(set(days_off)):
>     doSomething
>
> is bound to confuse most readers.
>
> Cheers - Chjas

If you have Python 2.7 or newer you don't need to recast:

if {"monday", "tuesday"}.intersection(days_off): doSomething