code: def mod(v):
      """3d vector length"""
      return np.sqrt(v[0] ** 2 + v[1] ** 2 + v[2] ** 2)
  
imports: from __future__ import absolute_import, division, print_function, unicode_literals
  import six
  from six.moves import zip
  import numpy
  import numpy.linalg
label_desc: Use image node_id 4 for calling a global function with example usage: mod(v) and returns: np