On Thu, Jan 31, 2013 at 8:52 AM, Dolph Mathews <dolph.mathews at gmail.com> wrote: > +1 for "X not in Y" > > "not X in Y" reads ambiguously to me. And there's the reason it matters...it actually is not ambiguous according to operator precedence rules (http://docs.python.org/2/reference/expressions.html#not-in): in "X not in Y" 'not' is part of the membership operator in "not X in Y" 'not' is a boolean operator on X, returning True or False These really are different operations that may have the same result for some data types and values. Phew! There is still only one way to do it right... dt -- Dean Troyer dtroyer at gmail.com