code: def get_elements(self, json_string, expr):
          
          load_input_json = self.string_to_json(json_string)
          # parsing jsonpath
          jsonpath_expr = parse(expr)
          # list of returned elements
          value_list = []
          for match in jsonpath_expr.find(load_input_json):
              value_list.append(match.value)
          if not value_list:
              return None
          else:
              return value_list
docs: Get list of elements from _json_string_, matching [http://goessner.net/articles/JsonPath/|JSONPath] expression.
  
          *Args:*\n
          _json_string_ - JSON string;\n
          _expr_ - JSONPath expression;
  
          *Returns:*\n
          List of found elements or ``None`` if no elements were found
  
          *Example:*\n
          | *Settings* | *Value* |
          | Library    | JsonValidator |
          | Library    | OperatingSystem |
          | *Test Cases* | *Action* | *Argument* | *Argument* |
          | Get json elements | ${json_example}=   | OperatingSystem.Get File |   ${CURDIR}${/}json_example.json |
          |                   |  ${json_elements}= | Get elements  |  ${json_example}  |  $.store.book[*].author |
          =>\n
          | [u'Nigel Rees', u'Evelyn Waugh', u'Herman Melville', u'J. R. R. Tolkien']