Python filter / max combo - checking for empty iterator

Question

(Using Python 3.1)

I know this question has been asked many times for the general question of testing if iterator is empty; obviously, there\'s no neat solution to t

Answer 1

def f(lst):
  flt = filter(lambda x : x is not None and x != 0, lst)
  try:
    return min(flt)
  except ValueError:
    return None

min throws ValueError when the sequence is empty. This follows the common "Easier to Ask for Forgiveness" paradigm.

EDIT: A reduce-based solution without exceptions

from functools import reduce
def f(lst):
  flt = filter(lambda x : x is not None and x != 0, lst)
  m = next(flt, None)
  if m is None:
    return None
  return reduce(min, flt, m)