> Is this the best way to test every item in a list? > > def alltrue(f,l): > return reduce(bool.__and__,map(f,l)) > > def onetrue(f,l): > return reduce(bool.__or__,map(f,l)) > >>>> alltrue(lambda x:x>1,[1,2,3]) > False >>>> alltrue(lambda x:x>=1,[1,2,3]) > True
As of Python2.5, there's an any() and all() function built into the language. >>> any(map(lambda x: x>1, [1,2,3])) >>> all(map(lambda x: x>1, [1,2,3])) Implementations for older versions are given at http://docs.python.org/lib/built-in-funcs.html You can adjust the "if" test in the example code so that it calls your function...something like def my_any(f, iterable): for element in iterable: if f(element): return True return False def my_all(f, iterable): for element in iterable: if not f(element): return False return True The advantage of the code in the docs is that it short-circuits...there's no need to reduce the entire list if an early item triggers the condition (a "true" early in an "any" or a "false" early in an "all"). While you can use a reduce(bool.__and__, thing) call, I more frequently see it as reduce(operator.or_, thing) Just a few ideas, -tkc -- http://mail.python.org/mailman/listinfo/python-list
