code: def show_completion_list(self, completions, completion_text=""):
          
          if not completions:
              return
          if not isinstance(completions[0], tuple):
              completions = [(c, '') for c in completions]
          if len(completions) == 1 and completions[0][0] == completion_text:
              return
          self.completion_text = completion_text
          # Sorting completion list (entries starting with underscore are
          # put at the end of the list):
          underscore = set([(comp, t) for (comp, t) in completions
                            if comp.startswith('_')])
  
          completions = sorted(set(completions) - underscore,
                               key=lambda x: str_lower(x[0]))
          completions += sorted(underscore, key=lambda x: str_lower(x[0]))
          self.show_completion_widget(completions)
docs: Display the possible completions