code: def tuple_to_string(self, k):
      str1 = "_".join(list(k))
      # print(k , "=>" , str1);
      return str1
  
file_path: atspy/atspy/TS/Signal_Grouping.py
imports: import pandas
  import numpy
  import itertools
  from .None import SignalHierarchy
label_desc: Use image node_id 2 for calling the cSignalGrouping obj's underlying member method code with example usage: obj.tuple_to_string(k) and returns: str1