code: def get_nom_val(atrv):
      """Given a string containing a nominal type, returns a tuple of the
      possible values.
  
      A nominal type is defined as something framed between braces ({}).
  
      Parameters
      ----------
      atrv : str
         Nominal type definition
  
      Returns
      -------
      poss_vals : tuple
         possible values
  
      Examples
      --------
      >>> get_nom_val("{floup, bouga, fl, ratata}")
      ('floup', 'bouga', 'fl', 'ratata')
      """
      r_nominal = re.compile("{(.+)}")
      m = r_nominal.match(atrv)
      if m:
          return tuple(i.strip() for i in m.group(1).split(","))
      else:
          raise ValueError("This does not look like a nominal string")
  
imports: from __future__ import division, print_function, absolute_import
  import re
  import itertools
  import datetime
  from functools import partial
  import numpy
  from scipy._lib.six import next
label_desc: Use image node_id 6 for calling a global function with example usage: get_nom_val(atrv) and returns: tuple