Google's foo.bar challenges

power_hungry.py

def answer(xs):
  negatives = []
  result = 0
  
  if len(xs) == 1:
    return xs[0]
  
  for element in xs:
    if element > 0:
      if result == 0:
        result = element
      else:
        result *= element
    elif element < 0:
      negatives.append(element)
      
  if negatives == [] or (len(negatives) == 1 and result == 0):
    return result
  
  if result == 0:
    result = 1
  
  result = reduce(lambda x, y: x * y, negatives) * result
  
  if len(negatives) % 2 == 0:
    return result
  else:
    return result / max(negatives)