On Oct 29, 2:43 am, Steven D'Aprano <st...@remove-this- cybersource.com.au> wrote: > On Thu, 28 Oct 2010 09:16:42 -0700, cbr...@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 > > Use a simple generator expression and any. > > if any(day in days_off for day in ['monday', 'tuesday']): > doSomething > > You (partially) defeat the short-circuiting behaviour of any() by using a > list comprehension. >
Good point, thanks. > If you have a lot of items to test against, make days_off a set instead > of a list, which makes each `in` test O(1) instead of O(N). For small N, > the overhead of creating the set is probably going to be bigger than the > saving, so stick to a list. > > Other than that, doing set operations is overkill -- it obfuscates the > intention of the code for very little gain, and possibly negative gain. > And as for the suggestion that you create a helper class to do the work, > that's surely the recommended way to do it in Java rather than Python. > Agreed. In the situation I am thinking of, N is generally very small, and readability trumps execution speed. Cheers - Chas > -- > Steven -- http://mail.python.org/mailman/listinfo/python-list
