code: def _extract_values(values_list):
          
          values = []
          # check if file or list of values to iterate
          if isinstance(values_list, str):
              with open(values_list) as ff:
                  reading = csv.reader(ff)
                  for j in reading:
                      values.append(j[0])
          elif isinstance(values_list, list):
              values = values_list
          else:
              raise Exception("input datatype not supported.")
          return values
docs: extract values from either file or list
  
          :param values_list: list or file name (str) with list of values