docstr: Parse a value of this type.
docstr_tok: ["Parse","a","value","of","this","type","."]
code: def parse_data(self, data_str):
      """
      Parse a value of this type.
      """
      if data_str in self.values:
          return data_str
      elif data_str == "?":
          return data_str
      else:
          raise ValueError(
              f"{str(data_str)} value not in {str(self.values)}"
          )
  
imports: import re
  import datetime
  import numpy
  import csv
  import ctypes
label_desc: Use image node_id 4 for calling the NominalAttribute obj's underlying member method code with example usage: obj.parse_data(data_str) and returns: data_str, data_str