<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def _URange(s):
 """Converts string to Unicode range. '0001..0003' => [1, 2, 3]. '0001' => [1]. Args: s: string to convert Returns: Unicode range Raises: InputError: the string is not a valid Unicode range. """

  a = s.split("..")
  if len(a) == 1:
    return [_UInt(a[0])]
  if len(a) == 2:
    lo = _UInt(a[0])
    hi = _UInt(a[1])
    if lo < hi:
      return range(lo, hi + 1)
  raise InputError("invalid Unicode range %s" % (s,))