code: def norm(
      input, ord=None, dim=None, keepdim=False, *, dtype=None, out=None
  ):
      if dim is None and (ord is not None):
          if input.ndim == 1:
              ret = ivy.vector_norm(
                  input, axis=dim, keepdims=keepdim, ord=ord
              )
          else:
              ret = ivy.matrix_norm(input, keepdims=keepdim, ord=ord)
      elif dim is None and ord is None:
          input = ivy.flatten(input)
          ret = ivy.vector_norm(input, axis=0, keepdims=keepdim, ord=2)
      if isinstance(dim, int):
          ret = ivy.vector_norm(
              input, axis=dim, keepdims=keepdim, ord=ord
          )
      elif isinstance(dim, tuple):
          ret = ivy.matrix_norm(
              input, axis=dim, keepdims=keepdim, ord=ord
          )
      return ret
  
imports: import math
  import ivy
  import ivy.functional.frontends.torch
  from ivy.functional.frontends.torch.func_wrapper import to_ivy_arrays_and_back
  from ivy.func_wrapper import with_supported_dtypes, with_unsupported_dtypes
  from collections import namedtuple
label_desc: Use image node_id 21 for calling a global function with example usage: norm(input, ord, dim, keepdim) and returns: ret