input: Write a python function to remove empty strings from a list.
  assert remove_empty_strings(["a", "", "b", "", "c", ""])==["a", "b", "c"]
  assert remove_empty_strings(["", "", "test", "", "data", ""])==["test", "data"]
  assert remove_empty_strings(["hello", "world", ""])==["hello", "world"]
output: def remove_empty_strings(lst):
      return [s for s in lst if s]