code: def var_tag(var):
      """Parse tag attribute of variable node."""
      tag = var.tag
      if (
          hasattr(tag, "trace")
          and len(tag.trace)
          and len(tag.trace[0]) == 4
      ):
          if isinstance(tag.trace[0][0], (tuple, list)):
              path, line, _, src = tag.trace[0][-1]
          else:
              path, line, _, src = tag.trace[0]
          path = os.path.basename(path)
          path = path.replace("<", "")
          path = path.replace(">", "")
          src = src.encode()
          return [path, line, src]
      else:
          return None
  
imports: from __future__ import absolute_import, print_function, division
  import numpy
  import os
  from functools import reduce
  from six import iteritems, itervalues
  import theano
  from theano import gof
  from theano.compile import Function
  from theano.compile import builders
  from theano.printing import pydot_imported, pydot_imported_msg
label_desc: Use image node_id 2 for calling a global function with example usage: var_tag(var) and returns: list, None