code: def ndim(a):
      """
      Return the number of dimensions of a tensor.
  
      Parameters
      ----------
      a : array_like
          Input tebsir.  If it is not already a tensor, a conversion is
          attempted.
  
      Returns
      -------
      number_of_dimensions : int
          The number of dimensions in `a`.  Scalars are zero-dimensional.
  
      See Also
      --------
      ndarray.ndim : equivalent method
      shape : dimensions of tensor
      Tensor.shape : dimensions of tensor
  
      Examples
      --------
      >>> import mars.tensor as mt
      >>> mt.ndim([[1,2,3],[4,5,6]])
      2
      >>> mt.ndim(mt.array([[1,2,3],[4,5,6]]))
      2
      >>> mt.ndim(1)
      0
  
      """
      from ..datasource import asarray
  
      try:
          return a.ndim
      except AttributeError:
          return asarray(a).ndim
  
label_desc: Use image node_id 1 for calling a global function with example usage: ndim(a) and returns: a, asarray