code: def is1d(a:Collection)->bool:
      "Return `True` if `a` is one-dimensional"
      return len(a.shape) == 1 if hasattr(a, 'shape') else Truf is1d(a:Collection)->bool:
      "Return `True` if `a` is one-dimensional"
      return len(a.shape) == 1 if hasattr(a, 'shape') else True
docs: Return `True` if `a` is one-dimensional