code: def filter_ctc_output(string_pred, blank_id=-1):
      """Apply CTC output merge and filter rules.
  
      Removes the blank symbol and output repetitions.
  
      Arguments
      ---------
      string_pred : list
          A list containing the output strings/ints predicted by the CTC system.
      blank_id : int, string
          The id of the blank.
  
      Returns
      -------
      list
          The output predicted by CTC without the blank symbol and
          the repetitions.
  
      Example
      -------
      >>> string_pred = ['a','a','blank','b','b','blank','c']
      >>> string_out = filter_ctc_output(string_pred, blank_id='blank')
      >>> print(string_out)
      ['a', 'b', 'c']
      """
  
      if isinstance(string_pred, list):
          # Filter the repetitions
          string_out = [i[0] for i in groupby(string_pred)]
  
          # Filter the blank symbol
          string_out = list(
              filter(lambda elem: elem != blank_id, string_out)
          )
      else:
          raise ValueError(
              "filter_ctc_out can only filter python lists"
          )
      return string_out
  
imports: from itertools import groupby
  from speechbrain.dataio.dataio import length_to_mask
  import math
  import dataclasses
  import numpy
  import heapq
  import logging
  import torch
  import warnings
  from typing import Dict, List, Optional, Union, Any, Tuple
label_desc: Use image node_id 1 for calling a global function with example usage: filter_ctc_output(string_pred, blank_id) and returns: string_out