docs: def natural_sort(item):
      """
      Sort strings that contain numbers correctly. Works in Python 2 and 3.
  
      >>> l = ['v1.3.12', 'v1.3.3', 'v1.2.5', 'v1.2.15', 'v1.2.3', 'v1.2.1']
      >>> l.sort(key=natural_sort)
      >>> l.__repr__()
      "['v1.2.1', 'v1.2.3', 'v1.2.5', 'v1.2.15', 'v1.3.3', 'v1.3.12']"
      """
      dre = re.compile(r'(\d+)')
      return [int(s) if s.isdigit() else s.lower() for s in re.split(dre, item)]