input: Write a python function to sort a list by separating positive and negative numbers, then sorting positive numbers in ascending order and negative numbers in descending order.
  assert sort_list([3, -2, -5, 0, 4, -1, 5]) == [0, 3, 4, 5, -1, -2, -5]
  assert sort_list([-10, 10, 0, 5, -5, -8, 7]) == [0, 5, 7, 10, -5, -8, -10]
  assert sort_list([0, -1, 1, -3, 3, -2, 2]) == [0, 1, 2, 3, -1, -2, -3]
output: def sort_list(lst):
      positives = sorted([x for x in lst if x > 0])
      negatives = sorted([x for x in lst if x < 0], reverse=True)
      zeros = [x for x in lst if x == 0]
      return zeros + positives + negatives