code: def get_var(var, default='""'):
      '''get var inside notebook'''
      ret = os.environ.get('NBCONVERT_' + var)
      if ret is None:
          return default
      return json.loads(retf get_var(var, default='""'):
      '''get var inside notebook'''
      ret = os.environ.get('NBCONVERT_' + var)
      if ret is None:
          return default
      return json.loads(ret)
docs: get var inside notebook