text: import csv
  import os
  all_dialogs = os.getcwd() + '/dialogs'
  os.chdir(all_dialogs)
  list_dialogs = os.listdir(all_dialogs)
  
  for i_dialogs in list_dialogs:
      ith_dialogs = os.getcwd() + "/" + i_dialogs
      os.chdir(ith_dialogs)
      ith_list = os.listdir(ith_dialogs)
      print("Dialogs Folder {}  # of tsv files: {}".format(i_dialogs, len(ith_list)))
      for m_tsv in ith_list:
          with open(m_tsv) as tsvfile:
              reader = csv.reader(tsvfile, delimiter='\t')
              name_col = []
              for row in reader:
                  name_col.append(row[1])
              if len(set(name_col)) <= 2:
                  print("Invalid tsv. Speakers < 3. Removing " + m_tsv)
                  os.remove(m_tsv)
      os.chdir(all_dialogs)
  